The leaders of the rival Koreas exchanged letters expressing hope for improved bilateral relations, which plummeted in the past three years amid a freeze in nuclear negotiations and North Korea’s accelerating weapons development.  North Korea’s state media said leader Kim Jong Un on Wednesday received a personal letter from outgoing South Korean President Moon Jae-in and replied on Thursday with his own letter appreciating Moon’s peace efforts during his term. Pyongyang’s official Korean Central News Agency said Friday their exchange of letters showed their “deep trust.” Moon in his letter to Kim acknowledged setbacks in inter-Korean relations but insisted that their aspirational vows for peace during their summits in 2018 and an accompanying military agreement aimed at defusing border area clashes remain relevant as a foundation for future cooperation. Moon also expressed hope for a resumption of nuclear talks between Washington and Pyongyang and for Kim to pursue cooperation with Seoul’s next government led by conservative President-elect Yoon Suk Yeol, Moon’s spokesperson Park Kyung-mee said. Tensions on the Korean Peninsula have risen since a series of North Korean weapons tests this year, including its first flight-test of an intercontinental ballistic missile since 2017 in March, reviving the nuclear brinkmanship aimed at forcing the U.S. to accept it as a nuclear power and to remove crippling sanctions. Also Read: North Korea tests new weapon bolstering nuclear capability South Korea’s military has also detected signs that North Korea is rebuilding tunnels at a nuclear testing ground it partially dismantled weeks before Kim’s first meeting with then-President Donald Trump in June 2018, a possible indicator that the country is preparing to resume nuclear explosive tests. Staking his single presidential term on inter-Korean rapprochement, Moon met Kim three times in 2018 and lobbied hard to help set up Kim’s meetings with Trump. But the diplomacy never recovered from the collapse of the second Kim-Trump meeting in 2019 in Vietnam, where the Americans rejected North Korea’s demands for major sanctions relief in exchange for dismantling an aging nuclear facility, which would have amounted to a partial surrender of its nuclear capabilities. Kim has since vowed to bolster his nuclear deterrent to counter “gangster-like” U.S. pressure and sped up his weapons development despite limited resources and pandemic-related difficulties. North Korea also severed all cooperation with Moon’s government while expressing anger over the continuation of U.S.-South Korea military exercises, which were curtailed in recent years to promote diplomacy with the North, and Seoul’s inability to wrest concessions from Washington on its behalf. KCNA said Moon wrote in his letter to Kim that he will continue to support efforts for Korean reunification based on their joint declarations for inter-Korean peace issued after their meetings in 2018. Kim and Moon shared views that “inter-Korean relations would improve and develop as desired and anticipated by the (Korean) nation if the (North and the South) make tireless efforts with hope,” KCNA said. South Korea’s next leader could take a harder line toward Pyongyang. Yoon, who takes office May 10, has rejected pursuing “talks for talks’ sake” with North Korea and vowed to bolster Seoul’s alliance with Washington and resume their full-scale military exercises to counter the North’s nuclear threat. Analysts say North Korea is also likely to escalate its weapons demonstrations in coming weeks or months to force a reaction from the Biden administration, which has been focused on Russia’s war on Ukraine and a rivalry with China. Also Read: North Korea fires ballistic missile in extension of testing The administration’s actions on North Korea have so far been limited to largely symbolic sanctions imposed over a series of missile tests this year and offers of open-ended talks that were quickly turned down by Pyongyang’s leadership. There are views in Seoul that Washington is slipping back to the Obama administration’s “strategic patience” policy of ignoring North Korea until it demonstrates seriousness about denuclearization, although that approach was criticized for neglecting a gathering nuclear threat. Biden’s special envoy for North Korea, Sung Kim, traveled to Seoul this week for meetings with senior South Korean officials and said they agreed on the need for a strong response to counter North Korea’s “destabilizing behavior.” After maintaining a conciliatory tone for years, Moon’s government objected more strongly to North Korea’s weapons tests this year, criticizing Kim’s government for ending its self-imposed suspension of long-range missile testing and urging a return to diplomacy. Seoul has also accused North Korea of destroying South Korean-owned facilities at the North’s Diamond Mountain resort where they ran tours together until 2008. Kim in 2019 called the South Korean facilities there “shabby” and ordered them destroyed, though the work was delayed by the coronavirus pandemic.    

North Korea claimed Thursday to have conducted the second successful test flight of a hypersonic missile, days after leader Kim Jong Un vowed to bolster his military forces despite pandemic-related difficulties. Wednesday’s launch, the North’s first known weapons test in about two months, indicates the country will press ahead with plans to modernize its nuclear and missile arsenals rather than return to disarmament talks anytime soon. The official Korean Central News Agency said the Central Committee of the ruling Workers’ Party expressed “great satisfaction” at the results of the missile test, which was observed by leading weapons officials. Hypersonic weapons, which fly at speeds in excess of Mach 5, or five times the speed of sound, could pose crucial challenges to missile defense systems because of their speed and maneuverability. It’s unclear whether and how soon North Korea could manufacture such a high-tech missile, but it was among a wish-list of sophisticated military assets that Kim disclosed early last year, along with a multi-warhead missile, spy satellites, solid-fueled long-range missiles and underwater-launched nuclear missiles. Read: North Korea fires suspected ballistic missile into sea Wednesday’s test was the second of its kind since North Korea first launched a hypersonic missile last September. “The successive successes in the test launches in the hypersonic missile sector have strategic significance in that they hasten a task for modernizing strategic armed force of the state,” a KCNA dispatch said. The word “strategic” implies the missile is being developed to deliver nuclear weapons. KCNA said the missile made a 120-kilometer-long (75 mile) lateral movement before hitting a target 700 kilometers (435 miles) away. It said the test reconfirmed the flight control and stability of the missile and verified its fuel capsule under the winter weather conditions. While North Korea appears to have made progress in the development of a hypersonic missile, it still needs more test flights to determine whether it meets its tactical objectives or how advanced a hypersonic weapon it could develop, said Lee Choon Geun, an expert and honorary research fellow at South Korea’s Science and Technology Policy Institute. A photo of the launch shows that the upper parts of the missiles launched in September and this week have different shapes. Lee said this suggests that North Korea is testing two versions of warheads for a missile still under development or it is actually developing two different types of hypersonic missiles. He said the missile’s reported lateral movement would provide the weapon with a greater maneuverability to evade enemy missile defense systems. Kim Dong-yub, a professor at the University of North Korean Studies in Seoul, said North Korea will likely go ahead with its arms build-up plans without being affected by external factors like the Beijing Olympics in February, the South Korean presidential election in March and a possible change in the Biden administration’s North Korea policy. “Given the U.S. has decided on a diplomatic boycott of the Beijing Olympics, North Korea doesn’t have to worry about what China would think when it conducts” weapons tests, Kim said. China is North Korea’s last major ally and aid benefactor. Some experts earlier predicted that North Korea would not launch any provocations until the Beijing Olympics ended. Tae Yongho, a former North Korean diplomat who now serves as a lawmaker in South Korea, wrote on Facebook that Pyongyang is keeping its borders shut due to fears about the pandemic. But he said Pyongyang is still working to perfect its missile technology to boost its position in any future negotiations. The North’s latest launch was first detected by its neighbors. Read: US urges NKorea to stop missile tests and return to talks The U.S. military called it a ballistic missile launch that “highlights the destabilizing impact of (North Korea’s) illicit weapons program,” while South Korea and Japan expressed concerns or regrets over the launch. China, for its part, called for dialogue and said that “all parties concerned should keep in mind the big picture (and) be cautious with their words and actions.” U.S.-led diplomacy on North Korea’s nuclear program remains stalled since 2019 due to disputes over international sanctions on the North. The Biden administration has repeatedly called for resuming the nuclear diplomacy “anywhere and at any time” without preconditions, but North Korea has argued the U.S. must first withdraw its hostility against it before any talks can restart. During last week’s plenary meeting of the Central Committee of the ruling Workers’ Party, Kim Jong Un repeated his vow to expand his country’s military capabilities without publicly presenting any new positions on Washington and Seoul. The North’s advancing nuclear arsenal is the core of Kim’s rule, and he’s called it “a powerful treasured sword” that thwarts potential U.S. aggressions. During his 10-year rule, he’s conducted an unusually large number of weapons tests to acquire an ability to launch nuclear strikes on the American mainland. But his country’s economy has faltered severely in the past two years due to the COVID-19 pandemic, the sanctions and his government’s own mismanagement.

North Korea said Wednesday it successfully tested a new hypersonic missile it implied was being developed as nuclear capable, as it continues to expand its military capabilities and pressure Washington and Seoul over long-stalled negotiations over its nuclear weapons. The missile test early Tuesday was North Korea's third round of launches this month and took place shortly before North Korea’s U.N. envoy accused the United States of hostility and demanded the Biden administration permanently end joint military exercises with South Korea and the deployment of strategic assets in the region. A photo published in North Korea's state media showed a missile mounted with a finned, cone-shaped payload soaring into the air amid bright orange flames. The official Korean Central News Agency said the missile during its first flight test met key technical requirements, including launch stability and the maneuverability and flight characteristics of the “detached hypersonic gliding warhead.” Read:North Korea fires suspected ballistic missile into sea The North’s announcement came a day after the South Korean and Japanese militaries said they detected North Korea firing a missile into its eastern sea. The U.S. Indo-Pacific Command said the launch highlighted “the destabilizing impact of (North Korea’s) illicit weapons program.” North Korea last week made offers to improve relations with the South if certain conditions are met, apparently returning to its pattern of mixing weapons demonstrations with peace overtures to wrest outside concessions. Negotiations over its nuclear program have been in a stalemate since February 2019. North Korea has demanded the lifting of U.S.-led sanctions while insisting it has the right to a nuclear weapons program. U.S. officials have made it clear the sanctions will stay in place until the North takes concrete steps toward denuclearization. North Korean leader Kim Jong Un in recent political speeches has vowed to bolster his nuclear deterrent in the face of U.S. pressure. His government has so far rejected the Biden administration’s offer to resume talks without preconditions, saying that Washington must abandon its “hostile policy” first, a term North Korea mainly uses to refer to sanctions and joint U.S.-South Korea military drills the North considers to be an invasion rehearsal. In a separate report, KCNA said the North’s rubber-stamp parliament opened a session on Tuesday and discussed domestic issues such as economic policies and youth education and that the meetings would continue. Some experts speculate the North might use the session to address the deadlock on nuclear diplomacy, but the state media report did not mention any comments made toward Washington and Seoul. Read:Seoul: North Korea fires 2 ballistic missiles off east coast At a ruling party meeting in January, Kim named hypersonic glide vehicles, which are launched from a rocket before gliding into a target, among a wish-list of sophisticated military assets. KCNA described the new missile as an important addition to the country’s “strategic” weaponry, implying that the system is being developed to deliver nuclear weapons. The report also said the test confirmed the stability of the missile’s fuel capsule, indicating a technology to add liquid propellant beforehand and keep it launch-ready for years. And a North Korean official said the North planned to expand the system to all its liquid-fuel missiles. Liquid-fuel missiles are more vulnerable than solid-fuel missiles because they need to be fueled separately and transported to launch sites using trucks that can be seen by enemy satellites or other military assets. Kim Dong-yub, a professor at the University of North Korean Studies in Seoul, said North Korea is trying to improve the mobility of these weapons. Last week, the influential sister of Kim Jong Un reached out to Seoul twice, saying her country was open to resuming talks and reconciliatory steps if conditions are met. Read: North Korea says it tested new long-range cruise missiles Analysts say North Korea is using the South’s desire for inter-Korean engagement to pressure Seoul to extract concessions from Washington on Kim's behalf as he renews an attempt to leverage his nuclear weapons for badly needed economic and security benefits. North Korea’s weapons displays could also be aimed at shoring up domestic unity as Kim Jong Un faces perhaps his toughest moment nearing a decade in rule, with pandemic border closures unleashing further shock on an economy battered by sanctions and decades of mismanagement. Experts say the North will likely continue its testing activity in the coming months as it dials up its pressure campaign, at least until China begins pushing for calm ahead of the Beijing Olympics early next year.

North Korean leader Kim Jong Un threatened to expand his nuclear arsenal as he disclosed a list of high-tech weapons systems under development, saying the fate of relations with the United States depends on whether it abandons its hostile policy, state media reported Saturday.

North Korean leader Kim Jong Un lifted a lockdown in a major city near the border with South Korea where thousands had been quarantined for weeks over coronavirus worries, state media said Friday.

North Korean leader Kim Jong Un made his first public appearance in 20 days as he celebrated the completion of a fertilizer factory near Pyongyang, state media said Saturday, ending an absence that had triggered global rumors that he may be seriously ill.

 President Donald Trump sent a personal letter to North Korean leader Kim Jong Un, seeking to maintain good relations and offering cooperation in fighting the viral pandemic, Kim's sister said Sunday.

North Korean leader Kim Jong Un has called for stronger anti-virus efforts to guard against COVID-19, saying there will be "serious consequences" if the illness spreads to the country.

The aunt of North Korean leader Kim Jong Un made her first public appearance in about six years, state media reported Sunday, quelling rumors that she was purged or executed by her nephew.