President Volodymyr Zelenskyy said on Sunday he was seeking a strong reaction from countries who have acknowledged that North Korea is becoming more involved in Russia’s more than 2-1/2-year-old war against Ukraine.

Speaking in his nightly video address, Zelenskyy said there was ample satellite and video evidence that North Korea was sending not only equipment to Russia, but also soldiers to be prepared for deployment.

“I am grateful to those leaders and representatives of states who do not close their eyes and speak frankly about this cooperation for the sake of a larger war,” he said. “We expect a normal, honest, strong reaction from our partners on this.”

Zelenskyy said greater North Korean involvement could only be harmful to everyone.

“Unfortunately, instability and threats can significantly increase after North Korea becomes trained for modern warfare,” he said.

“If the world remains silent now and we have to engage soldiers from North Korea on the front line in the same way we have to defend ourselves from (Iranian) Shahed drones, this will certainly benefit no one in the world and only prolong the war.”

North Korea’s actions, he said, meant “in effect yet another country entering the war against Ukraine.”

Zelenskyy last week accused North Korea of deploying officers alongside Russia and preparing to send thousands of troops to help Moscow’s war effort. South Korea’s spy agency said on Friday North Korea had dispatched 1,500 special forces troops to Russia’s Far East for training.

U.S. Defense Secretary Lloyd Austin said on Saturday he could not confirm reports that North Korea has sent troops to Russia ahead of a possible deployment, but said such a move would be concerning, if true. NATO chief Mark Rutte said on Thursday there was no evidence of Pyongyang’s presence at this stage.

The involvement of North Korean regular troops to support Russia’s invasion of Ukraine would be a serious escalation of the war, France and Ukraine’s foreign ministers said at a joint press conference in Kyiv on Saturday.