WASHINGTON — The Biden administration has said that around 8,000 soldiers from North Korea are now in Russia near Ukraine's border and are preparing to help the Kremlin fight against Ukrainian troops in the coming days.

The new figure is a dramatic increase from a day earlier, when Defence Secretary Lloyd Austin would only say "some" of the troops had moved toward Ukraine’s border in the Kursk region, where Moscow's forces have struggled to push back a Ukrainian incursion.

It would also mean most of the North Korean troops that the US and its allies say have been sent to Russia are now on the Russia-Ukraine border.

"DPRK [North Korea] participation in combat against Ukraine would be an alarming expansion of the conflict. Already, the DPRK's troop deployment in Russia marks a dangerous expansion in Russian-DPRK ties," Robert A. Wood, the Deputy US Ambassador to the United Nations, said at a Security Council session.

"Russia's actions with respect to the DPRK are not only dangerous, but they are antithetical to its responsibility as a permanent member of this UN Security Council. Russia's military cooperation with the DPRK violates multiple UN Security Council resolutions, which prohibit both procuring DPRK arms and providing military training."

The US has estimated a total of 10,000 North Korean troops are in Russia. Seoul and its allies said that the number has increased to 11,000, while Ukraine has put the figure higher, at up to 12,000.

Ukraine's president Volodymyr Zelenskyy said that while North Korean troops have been deployed to Kursk, they have not yet taken part in any hostilities.

"They are already in the Kursk region. They will use these troops. Of course, these people will die. Of course, they will try to do everything to make sure that more North Korean soldiers die, which means that they will push more of them forward than Russia. And so we will see these victims with you," he said in an interview with South Korean television channel, KBS.

North Korea's move to deepen its relationship with Russia has raised concerns around the world about how that may expand the war and what Russian military aid will be delivered in exchange.

It was a key topic as US and South Korean leaders met this week in Washington, fuelling concerns that the presence of the North Korean troops could further destabilise the Asia-Pacific region and broaden Moscow's war on Ukraine.

South Korean Foreign Minister Cho Tae-yul condemned the deployment "in the strongest possible terms" and called for an immediate withdrawal of the troops.

North Korea's belligerent actions not only places the European continent but also the Korean peninsula under threat and that Seoul agrees "to take necessary measures accordingly," he said.

There are also questions about what new military technologies North Korea might get from Russia in exchange for the deployment and whether it might lead other nations to send their own forces to fight in the war.

Meanwhile, the Director of the United Nations Office for Disarmament Affairs told the Security Council that both Russia and Ukraine have continued to receive arms, ammunition and other forms of military assistance from other countries, fuelling the fighting.

"Recent reports also refer to the presence of third party military personnel in the Russian Federation to assist in military operations against Ukrainian forces. We urge all concerned to refrain from any steps that may lead to further spill over and intensification of the war," Adedeji Ebo said. — Euronews