SOUTH Korea demanded today that North Korea immediately pull out its troops allegedly deployed in Russia, as it summoned the Russian ambassador to protest against deepening military co-operation between Pyongyang and Moscow.

South Korea’s spy agency said on Friday it had confirmed that North Korea sent 1,500 special operation forces to Russia this month to support Moscow’s war against Ukraine.

Ukrainian President Volodymyr Zelensky said earlier that his government had intelligence that 10,000 North Korean soldiers were being prepared to join invading Russian forces.

During a meeting with Russian ambassador Georgy Zinoviev, South Korean Foreign Minister Kim Hong Kyun “condemned in the strongest terms” North Korea’s troop dispatch that he said posed “a grave security threat” to South Korea and the international community.

Mr Kim said that South Korea in collaboration with the international community will mobilise all available means to deal with an act that threatens its vital national security interests, according to the statement.

The Russian embassy quoted Mr Zinoviev as saying that the Russian-North Korean co-operation is not aimed against the security interests of South Korea.

In a telephone call with Nato secretary-general Mark Rutte today, South Korean President Yoon Suk Yeol said that Seoul won’t sit idly by in the face of “reckless” military co-operation between Pyongyang and Moscow.

Mr Rutte wrote on Twitter that North Korea possibly fighting alongside Russia would “mark a significant escalation.”

British and US special forces were exposed as having been deployed to Ukraine late in 2022.

Meanwhile, US Defence Secretary Lloyd Austin arrived in Kiev on an unannounced visit today, hours after a Russian drone attack on the Ukrainian capital.

Mr Austin said on Twitter that his fourth visit shows “that the United States, alongside the international community, continues to stand by Ukraine.”

Ukraine is struggling to hold back Russian advances along the eastern front through the Donbass.

Mr Zelensky is urging Western allies to support his so-called “victory plan” to end the almost three-year war, which is Europe’s biggest conflict since World War II and has cost tens of thousands of lives on both sides, including many civilians.

His strategy includes a formal invitation for Ukraine to join Nato and permission to use Western long-range missiles to strike military targets in Russia — steps that Kiev’s allies have previously baulked at supporting.

The Western response has been lukewarm, and Mr Austin was expected to discuss the plan with Ukrainian officials in Kiev.

A Russian missile attack on the southern city of Zaporizhzhia injured seven people in the city centre and caused huge damage to civilian infrastructure, including a kindergarten and more than 30 residential buildings, regional governor Ivan Fedorov said.

Machine gun fire and the noise of drones’ engines was also heard in Kiev’s centre throughout the night. Authorities reported minor damage to civilian infrastructure caused by falling drone debris in the three districts of the city.

Russia fired three missiles and more than 100 drones at Ukraine overnight from Sunday to today, Ukraine’s air force said.