The United States, Japan and South Korea condemned North Korea's latest launch of an intercontinental ballistic missile in a joint statement, while the United Nations, European Union, and Germany also condemned the missile test, which demonstrated a potential advancement in its ability to launch long-range nuclear attacks on the mainland U.S.

North Korea said it tested an ICBM earlier on Thursday, upgrading what it called the "world's most powerful strategic weapon," as Seoul warned Pyongyang could get missile technology from Russia for helping with the war in Ukraine.

The U.S. State Department said Secretary of State Antony Blinken held a call with the foreign ministers of Japan and South Korea in which they condemned the launch and called it a "flagrant violation of multiple U.N. Security Council resolutions."

The U.S., South Korea and Japan released a joint statement Thursday condemning the missile launch, saying it was in "flagrant violation" of numerous U.N. Security Council resolutions. The foreign ministers of the three countries also condemned the deepening military cooperation between North Korea and Russia, particularly the deployment of North Korean troops to Russia.

"We strongly urge (North Korea) to immediately cease its series of provocative and destabilizing actions that threaten peace and security on the Korean Peninsula and beyond," they said.

U.N. Secretary-General Antonio Guterres strongly condemned the launch, which clearly violates U.N. Security Council resolutions banning North Korea’s use of ballistic missile technology, the U.N. spokesman said.

The U.N. chief reiterated his call for de-escalation on the Korean peninsula and establishing an environment for dialogue and the resumption of talks, stressing that "Diplomatic engagement remains the only pathway to sustainable peace and the complete and verifiable denuclearization of the Korean Peninsula," spokesman Stephane Dujarric said.

EU 'strongly condemns' N.Korea missile launch

The European Union on Thursday "strongly" condemned North Korea's test-firing of a long-range ballistic missile as a "flagrant violation" of UN Security Council resolutions.

"This illegal launch shows the DPRK's continued intention to develop the means to deliver weapons of mass destruction," said a statement from EU foreign policy chief Josep Borrell, who heads Friday to Japan then South Korea for security and defense talks.

Germany condemns 'illegal' North Korea ICBM missile launch

Germany also strongly condemned what it called North Korea's "illegal" launch of an intercontinental ballistic missile and urged Pyongyang to refrain from further escalation, a foreign ministry spokesperson said.

Germany has joined other nations in condemning the launch by North Korea, whose involvement on Russia's side in the war in Ukraine has also triggered concern in recent days.

Jung Chang Wook, head of the Korea Defense Study Forum think tank in Seoul, said it's fair to say the missile in Thursday's launch could carry North Korea's biggest and most destructive warhead. He said the launch was also likely designed to test other technological aspects that North Korea needs to master to further advance its ICBM program.

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. U.S. Defense 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.

Lee Choon Geun, an honorary research fellow at South Korea’s Science and Technology Policy Institute, said the early results of Thursday’s launch suggested Russia might have given a key propellant component that can boost a missile’s engine thrust. He said that a higher thrust allows a missile to carry a bigger payload, fly with more stability and hit a target more accurately.

Jung said he 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.

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 kilometers (6,200 to 9,300 miles) that could reach any location on Earth," Kwon said.

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

"North Korea could have probably thought that its rivals could look down it after it gave away so much in military resources to Russia," Yang Uk, an expert at South Korea’s Asan Institute Institute for Policy Studies. "The launch may have been intended as a demonstration to show what it’s capable of, regardless of troop dispatches or other movements.

In the past two years, Kim has used Russia’s invasion of Ukraine as a window to ramp up weapons tests and threats while also expanding military cooperation with Moscow. South Korea, the U.S. and others say North Korea has already shipped artillery, missiles and other conventional arms to replenish Russia's dwindling weapons stockpiles.

North Korea’s possible participation in the Ukraine war would mark a serious escalation. Besides Russian nuclear and missile technologies, experts say Kim Jong Un also likely hopes for Russian help to build a reliable space-based surveillance system and modernize his country's conventional weapons. They say Kim will likely get hundreds of millions of dollars from Russia for his soldiers' wages if they are stationed in Russia for one year.

Zelenskyy slams 'zero' Western response to N. Korean troop deployment

Meanwhile, Ukraine's President Volodymyr Zelenskyy criticized Western allies for not adequately responding to the involvement of North Korean troops in Russia's war with Kyiv.

The comments came after the U.S. and South Korean defense chiefs called on Pyongyang to withdraw its troops from Russia, warning that North Korean soldiers in Russian uniforms were being deployed for possible action against Ukrainian forces.

Russian President Vladimir Putin is "testing the reaction of the West, of NATO states and the reaction of South Korea," the Ukrainian leader said in an interview with the South Korean television channel KBS.

"And if there is nothing – and I think that the reaction to this is nothing, it has been zero – then the number of North Korean troops on our border will be increased," he added.

Seoul has long accused the nuclear-armed North of sending weapons to help Moscow fight Kyiv and alleges that Pyongyang moved to deploy soldiers en masse after its leader Kim Jong Un signed a mutual defense deal with Putin in June.

"I am surprised by China's silence. I am not saying that China is on our side, but it is one of the guarantors of security in your region, at least that's what we thought," Zelenskyy said, adding, "and there is this silence now."

"I think, Japan, South Korea – you are both strong countries – should reach out to China and have China as an ally in terms of what North Korea is doing now," he added.

"North Korea is now dragging your whole region into a war," the Ukrainian leader said.

His office released the comments as the United States and South Korea held high-level talks after North Korea test-fired one of its newest and most powerful missiles, demonstrating its threat to the U.S. mainland days ahead of elections.