Kyiv [Ukraine], October 29: The United States will not impose new limits on Ukraine's use of American weapons if North Korea enters the fight.
The Pentagon said, as NATO said North Korean military units had been deployed to Russia's Kursk region.
The North Korea deployment is fanning Western concerns that the 2-1/2-year conflict in Ukraine could widen, even as attention shifts to the Middle East.
It could be a sign of how Russia hopes to offset mounting battlefield losses and continue making slow, steady gains in eastern Ukraine.
"The deepening military cooperation between Russia and North Korea is a threat to both Indo-Pacific and Euro-Atlantic security," NATO Secretary-General Mark Rutte told reporters after talks with a South Korean delegation about the North Korean deployments.
U.S. President Joe Biden said the development was "very dangerous."
The Pentagon estimated 10,000 North Korean troops had been deployed to eastern Russia for training, up from an estimate of 3,000 troops last Wednesday.
"A portion of those soldiers have already moved closer to Ukraine, and we are increasingly concerned that Russia intends to use these soldiers in combat or to support combat operations against Ukrainian forces in Russia's Kursk Oblast near the border with Ukraine," said Pentagon spokesperson Sabrina Singh, using a term for a Russian region.
Ukrainian military intelligence said on Thursday that the first North Korean units had been recorded in the Kursk border region, where Ukrainian troops have been operating since staging a major incursion in August.
But the Pentagon declined to confirm that North Korean forces were already in Kursk.
"It is likely that they are moving in that direction towards Kursk. But I don't have more details just yet," Singh said.
Ukrainian Foreign Minister Andrii Sybiha said Kyiv had been warning about the deployment for weeks, and accused allies of failing to deliver a strong response.
"The bottom line: listen to Ukraine. The solution: lift restrictions on our long-range strikes against Russia now," he said on X.
The Kremlin had initially dismissed reports about a North Korean deployment as "fake news".
But Putin on Thursday did not deny North Korean troops were in Russia and said that it was Moscow's business how to implement a partnership treaty with Pyongyang.
A North Korean foreign ministry official did not confirm media reports about a troop deployment to Russia but said if Pyongyang had taken such action, he believed it would be in line with international norms.
The deployment of North Korean troops was a sign of "growing desperation" on Putin's part, Rutte said.
"Over 600,000 Russian soldiers have been killed or wounded in Putin's war and he is unable to sustain his assault on Ukraine without foreign support," Rutte said.
The Ukrainian president's chief of staff, Andriy Yermak, said sanctions alone would not be a sufficient response to North Korean involvement.
He added that Kyiv needs "weapons and a clear plan to prevent North Korea's expanded involvement".
"The enemy understands strength. Our allies have this strength," Yermak said on X.
Source: Fijian Broadcasting Cooperation