North Korean troops are in Russia, US defense secretary says

Austin said it would "very, very serious" if they are preparing to fight alongside Russia in Ukraine, as Kyiv has alleged.

"There is evidence that there are DPRK troops in Russia," Austin told reporters in Rome, using North Korea's formal name - the Democratic People's Republic of Korea.

"What exactly they are doing? Left to be seen. These are things that we need to sort out," Austin added.

Ukrainian President Volodymyr Zelenskiy has cited intelligence about the preparation of two units with possibly up to 12,000 North Korean troops who would take part in the war alongside Russian forces.

"We'll continue to pull this thread and see what happens here," Austin said of the intelligence analysis. "If they are co-belligerents, (if) their intention is to participate in this war on Russia's behalf, that is a very, very serious issue."

The Kremlin has dismissed assertions that North Korea may have sent some military personnel to help Russia against Ukraine.

Since their leaders met in Russia's Far East last year, North Korea and Russia have upgraded their military ties. They met again in June to sign a comprehensive strategic partnership that includes a mutual defense pact.

U.S. officials, speaking on condition of anonymity, say Russia has suffered more than 600,000 casualties of killed and wounded troops in the 2 1/2 year old war in Ukraine.

Austin said the North Korean deployment could be further evidence of the Russian military's manpower issues.

"This is an indication that he may be even in more trouble than most people realize," Austin said.

"But again, (Russian President Vladimir Putin) went tin cupping early on to get additional weapons and materiels from DPRK and then from Iran. And now he's making a move to get more people, if that is the case, if these troops are designed to be a part of the fight in Ukraine."

South Korea's spy agency said last week that North Korea has shipped 1,500 special forces troops to Russia's Far East for training and acclimatizing at local military bases and were likely to be deployed for combat in the war in Ukraine.

South Korea's National Intelligence Service said it had been working with the Ukrainian intelligence service and had used facial recognition technology to identify North Korean officers in eastern Ukraine's Donetsk region supporting Russian forces firing North Korean missiles.

North Korea has shipped artillery rounds, ballistic missiles and anti-tank rockets to Russia in more than 13,000 containers since August last year, the agency said, based on the remnants of weapons recovered from the battlefront in Ukraine.

In all, more than eight million artillery and rocket rounds have been shipped to Russia, it said.