North Korean leader Kim Jong Un vowed to redouble efforts to make his nuclear force fully ready for combat with the United States and its allies, state media reported Tuesday, after the country disclosed a new platform likely designed to fire more powerful intercontinental ballistic missiles targeting the mainland U.S.

Kim has repeatedly made similar pledges, but his latest threat comes as outside experts believe Kim will perform provocative weapons tests ahead of the U.S. presidential election in November. In recent days, North Korea has also resumed launches of trash-carrying balloons toward South Korea.

In a speech marking the 76th founding anniversary for his government on Monday, Kim said North Korea faces “a grave threat” because of what he called “the reckless expansion” of a U.S.-led regional military bloc that is now developing into a nuclear-based one. Kim said such a development is pushing North Korea to boost its military capability, according to the official Korean Central News Agency.

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Kim said North Korea will “redouble its measures and efforts to make all the armed forces of the state including the nuclear force fully ready for combat,” KCNA said.

North Korea has been protesting the July signing of a new U.S.-South Korean defense guideline meant to integrate U.S. nuclear weapons and South Korean conventional weapons to cope with growing North Korean nuclear threats. North Korea said the guideline revealed its adversaries’ plots to invade the country. U.S. and South Korean officials have repeatedly said they don't intend to attack the country.

Since 2022, North Korea has significantly accelerated its weapons testing activities in a bid to perfect its capabilities to launch strikes on the U.S. and South Korea. The U.S. and South Korea have responded by expanding military drills that North Korea calls invasion rehearsals.

Many analysts believe North Korea has some last remaining technological barriers to overcome to acquire long-range nuclear missiles that can reach the U.S. mainland, though it likely already possesses missiles that can hit key targets in South Korea and Japan.

South Korean officials and experts say North Korea could conduct nuclear tests or ICBM test-launches before the U.S. election to increase its leverage in future diplomacy with the U.S. Observers say North Korea likely thinks a greater nuclear capability would help it win U.S. concessions like sanctions relief.

North Korea as of Tuesday morning did not appear to have staged any major military demonstration to mark this year’s anniversary. But the North's main Rodong Sinmun newspaper on Sunday published a photo of Kim inspecting what appeared to be a 12-axle missile launch vehicle, which would be the largest the country has shown so far, during a visit to a munitions plant. This sparked speculation that the North could be developing a new ICBM that is bigger than its current Hwasong-17 ICBM, which is launched on an 11-axle vehicle.

When asked about the photo on Monday, Pentagon spokesperson Maj. Gen. Pat Ryder refused to provide a specific assessment of North Korea’s missile capabilities and reiterated that Washington was working closely with Seoul, Tokyo and other partners to preserve regional security and deter potential attacks.

“It’s not unusual for North Korea to use media reports and imagery to try to telegraph, you know, to the world,” he said.

North Korea flew hundreds of huge balloons carrying rubbish toward South Korea for five straight days through Sunday, extending a Cold War-style psychological warfare campaign that has further stoked animosities on the Korean Peninsula. The balloons largely contained waste papers and vinyl, and there has been no repots of major damage.

North Korea began its balloon campaign in late May, calling it a response to South Korean civilians flying propaganda leaflets across the border via their own balloons. South Korea later restarted its anti-Pyongyang propaganda loudspeaker broadcasts along the rivals' tense land border.

Observers say North Korea is extremely sensitive to South Korean leafleting activities and loudspeaker broadcasts as they could hamper its efforts to ban foreign news to its 26 million people.