North Korea has sent another 8,500 troops to Russia, CNN reports.
According to a Ukrainian intelligence official, 400 of these troops are drone operators.
It should be noted that Russia and North Korea signed a mutual defense agreement two years ago. Under the agreement, the countries may deploy military forces to each other's territory for the purpose of providing military assistance.
Russian officials have acknowledged in a number of statements that North Korean troops have fought against Ukraine as part of the Russian army.