Russian Foreign Minister Sergei Lavrov said North Korea has affirmed its “clear support” for Russia’s war in Ukraine and for Kremlin leadership as he started a three-day visit to Pyongyang.

North Korea is set to treble the number of its troops fighting for Russia along the front lines with Ukraine, sending an additional 25,000 to 30,000 soldiers to assist Moscow, according to an intelligence assessment from Ukrainian officials.

Russia’s foreign minister has warned the U.S., South Korea and Japan against forming a security partnership targeting North Korea.