North Korean leader Kim Jong Un toured the country’s key weapons factories, including those producing artillery systems and launch vehicles for nuclear-capable ballistic missiles, and pledged to speed up efforts to advance his military’s arms and war readiness, state media said Sunday.

Kim’s three-day inspections through Saturday came as the United States and South Korea prepared for their next round of combined military exercises planned for later this month to counter the growing North Korean threat.

Tensions on the Korean Peninsula are at their highest level in years as the pace of North Korea’s missile tests and the joint U.S.-South Korea military drills, which Kim portrays as invasion rehearsals, have both intensified in a tit-for-tat cycle.

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Some experts say Kim’s tour of the weapons factories could also be related to possible military cooperation with Moscow that may involve North Korean supplies of artillery and other ammunition as Russian President Vladimir Putin reaches out to other countries for support in the war in Ukraine. Koo Byoungsam, spokesperson of South Korea's Unification Ministry, which handles inter-Korean affairs, said Friday that Kim's staged visits to the arms factories are possibly aimed at both demonstrating North Korea's military might in the face of U.S.-South Korean drills and also communicating an intent to export weapons.

“We express deep regret that North Korea continues to develop nuclear weapons and ICBMs (intercontinental ballistic missiles) as well as conventional weapons at the expense of the wellbeing of its citizens,” Koo said during a briefing.

During a visit to an unspecified factory producing large-caliber artillery systems, Kim stressed the facility’s “important responsibility and duty” in further boosting his military’s “war preparations,” North Korea’s official Korean Central News Agency said.

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Kim praised the factory’s efforts to employ “scientific and technological measures” to improve the quality of shells, reduce processing times for propellent tubes and increase manufacturing speed. He also urged the factory to move ahead with development and large-scale production of new kinds of ammunition, the KCNA said.

Kim echoed the message in visits to two other factories, calling the delivery of launcher trucks designed to transport and fire ballistic missiles “a top priority” for the military and urging for the “rapid expansion” of production of more reliable engines for cruise missiles and drones.

North Korean photos showed Kim walking past huge launcher trucks designed for intercontinental ballistic missiles which recent tests indicated they could potentially reach the U.S. mainland. Other photos showed Kim firing scoped rifles during a visit to a small arms factory where he said soldiers' firearms need to be modernized, according to KCNA.

In the face of deepening confrontations with Washington and Seoul, Kim has been trying boost the visibility of his partnerships with Moscow and Beijing as he tries to break out of diplomatic isolation and insert himself into a united front against the United States.

His tour of the weapons factories comes after a giant military parade last month in North Korea’s capital, Pyongyang, where Kim was joined by Russian Defense Minister Sergei Shoigu and a Chinese ruling party official while rolling out his most powerful missiles designed to target South Korea and the United States.

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Shoigu’s presence at the July 27 parade, which came after Kim took him on a tour of a domestic arms exhibition, demonstrated North Korea’s support for Russia’s invasion of Ukraine and added to suspicions the North was willing to supply arms to Russia to support its war efforts.

Cheong Seong Chang, an analyst at South Korea’s Sejong Institute, said Kim’s visits to the factories likely had a dual goal of encouraging the modernization of domestically produced weapons and examining artillery and other supplies that can possibly be exported to Russia.

Kim’s comments at the artillery factory about improving the quality of shells and the need to develop new types of ammunition, which he described as key to the country’s “national defense economic work,” clearly communicate an intent for exports to Russia, Cheong said.

When asked whether North Korea has ever used the term “national economic work” in government comments before, Koo didn't answer directly but described it as “very rare.”

“If they meant arms exports with this, then they are openly pledging to violate U.N. Security Council resolutions, and I think that would be deplorable,” Koo said.

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North Korea has been aligning with Russia over the war in Ukraine, insisting that the “hegemonic policy” of the U.S.-led West forced Moscow to take military action to protect its security interests. But Pyongyang has denied U.S. accusations that it has been providing arms to Russia to aid its fighting in Ukraine.

Cheong said Kim’s comments at the factory about making missile-launch trucks could indicate that the North is seeing some progress in increasing the production of those vehicles, which would possibly improve the operational range of its ballistic weapons designed to target neighboring rivals and the U.S. mainland.