North Korea test-fired an intercontinental ballistic missile for the first time in almost a year on Thursday, demonstrating a potential advancement in its ability to launch long-range nuclear attacks on the mainland U.S.

The launch was likely meant to meant grab American attention days ahead of the Nov. 5 election and respond to condemnation over the North's reported troop dispatch to Russia to support its war against Ukraine. Some experts speculated Russia might have provided technological assistance to North Korea over the launch.

North Korean leader Kim Jong-un observed the launch, calling it "an appropriate military action" to show his country's resolve to respond to its enemies' moves that have threatened the North's safety, according to North Korean state media.

Kim said the enemies' "various adventuristic military manouevres" highlighted the importance of North Korea's nuclear capability. He reaffirmed that North Korea will never abandon its policy of bolstering its nuclear forces.

North Korea has steadfastly argued that advancing its nuclear capabilities is its only option to cope with the expansion of U.S.-South Korean military training, though Washington and Seoul have repeatedly said they have no intention of attacking North Korea. Experts say North Korea uses its rivals' drills as a pretext to enlarge its nuclear arsenal to wrest concessions when diplomacy resumes.

Increasing co-operation with Russia

The North Korean statement came hours after its neighbours said they had detected the North's first ICBM test since December 2023, and condemned it as a provocation that undermines international peace.

South Korea's Joint Chiefs of Staff said North Korea could have tested a new, solid-fuelled long-range ballistic missile on a steep angle, an attempt to avoid neighbouring countries. Missiles with built-in solid propellants are easier to move and hide and can be launched more quickly than liquid-propellant weapons.

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Japanese Defence Minister Gen Nakatani told reporters the missile's flight duration of 86 minutes and its maximum altitude of more than 7,000 kilometres exceeded corresponding data from previous North Korean missile tests.

Having a missile fly higher and for a longer duration than before means its engine thrust has improved. Given that previous ICBM tests by North Korea have already proved they can theoretically reach the U.S mainland, the latest launch was likely related to an effort to examine whether a missile can carry a bigger warhead, experts say.

Kwon Yong Soo, an honorary professor at South Korea's National Defense University, said that North Korea likely tested a multiple-warhead system for an existing ICBM.

"There's no reason for North Korea to develop another new ICBM when it already has several systems with ranges of up to 10,000 to 15,000 kilometres that could reach any location on Earth," Kwon said.

North Korea has made strides in its missile technologies in recent years, but many foreign experts believe the country has yet to acquire a functioning nuclear-armed missile that can strike the U.S. mainland. They say North Korea likely possesses short-range missiles that can deliver nuclear strikes across all of South Korea.

There have been concerns that North Korea might seek Russian help to perfect its nuclear-capable missiles in return for its alleged dispatch of thousands of troops to support Russia's war against Ukraine. Jung speculates Russian experts might have given technological advice on missile launches since Russian President Vladimir Putin visited North Korea for a meeting with Kim in June.

U.S. Defence Secretary Lloyd Austin said Wednesday that North Korean troops wearing Russian uniforms and carrying Russian equipment are moving toward Ukraine, in what he called a dangerous and destabilizing development.

The North Korean confirmation of an ICBM test was unusually quick, since North Korea usually describes its weapons tests a day after they occur.

Test comes as U.S., South Korean officials meet

U.S. National Security Council spokesperson Sean Savett called the launch "a flagrant violation" of multiple UN Security Council resolutions that "needlessly raises tensions and risks destabilizing the security situation in the region." Savett said the U.S. will take all necessary measures to ensure the security of the American homeland and its South Korean and Japanese allies.

The deployment of up to 12,000 North Korean troops to Russia has become a key topic as U.S. and South Korean leaders meet in Washington this week.

Austin, Secretary of State Antony Blinken and other U.S. officials will hold talks Thursday with South Korean Foreign Minister Cho Tae-yul and Defence Minister Kim Yong-hyun.

Ukraine's ambassador to the United Nations, Sergiy Kyslytsya, said at an emergency meeting of the UN Security Council on Wednesday that as many as 4,500 North Korean troops are expected to be at the border this week and to begin directly participating in combat operations against Ukrainian forces in November.

North Korea has also provided munitions to Russia, and earlier this month, the White House released images it said were of North Korea shipping 1,000 containers of military equipment there by rail.