Russia is helping Pyongyang evade sanctions and develop its nuclear capabilities in return for North Korean troops and missiles, Ukraine’s military intelligence chief Kyrylo Budanov told The Economist in comments published on Oct. 22.

Budanov previously revealed that close to 11,000 North Korean troops are already in Russia and will be ready to fight by Nov. 1.

The move would signal deepening military cooperation between Moscow and Pyongyang, with North Korea already providing Russia with artillery shells and ballistic missiles for war against Ukraine.

Russia’s support in nuclear capabilities includes providing technologies for smaller tactical nuclear weapons and submarine missile-launch systems, Budanov claimed.

The sanctions evasion can also be vital for North Korea, which faces heavy economic restrictions over its nuclear program. Russia has blocked the renewal of a U.N. monitoring program overseeing Pyongyang’s nuclear and ballistic missile development.

Speaking to The Economist, the Ukrainian spy chief said that the military personnel sent to Russia included 500 officers and three generals. A contingent of 2,600 troops should allegedly soon arrive in Kursk Oblast, a Russian border region partially held by Ukraine.

North Korean troops are currently undergoing training in Khabarovsk Krai in Russia’s far east, Budanov said.

According to him, Pyongyang has also supplied Russia with 2.8 million artillery shells and an unspecified number of ballistic missiles, which are serviced by North Korean crews.

Kyiv and Seoul have repeatedly sounded alarm on North Korea transferring personnel to Russia, though the reports have not been confirmed by the U.S. or other Western officials.

North Korea has denied the reports, while a Kremlin spokesperson gave an evasive answer on the issue.

President Volodymyr Zelensky urged Ukraine’s allies to mount pressure on North Korea, calling for a “concrete response” to the country’s escalating military support of Russia’s full-scale war.

Two North Korean brigades of up to 6,000 personnel each are currently undergoing training in Russia, Zelensky said in his evening address, citing military intelligence reports. He also said that impoverished North Korea is likely receiving financial support for its military aid.