Russia is gearing up to deploy as many as 50,000 North Korean soldiers against Kyiv, Ukrainian President Volodymyr Zelensky warned Sunday while calling on South Korea to boost cooperation with Ukraine on air-defense systems and drones. Zelensky said in a televised interview that Russia and North Korea decided to station 30,000 to 50,000 DPRK troops in Russia, a move that also poses a threat to Asian states, including South Korea. “North Koreans appear on the territory of the Russian Federation from time to time,” he said, adding that their presence has expanded from earlier estimates of hundreds of personnel.