If there are images they are a reflection of something,’ he said in a tongue-in-cheek answer to whether Pyongyang had sent troops to help with Russia’s war in Ukraine.

The first group of North Korean troops have been sent to the Russian region of Kursk where some have tried to desert, according to reports. Ukraine launched an incursion into the Russian region on August 6 and Putin is said to be planning to use the North Korean soldiers in his fight to recapture territory.

The U.S. government said it had evidence that at least 3,000 North Korean soldiers were being trained in Russia.

Chinese President Xi Jinping told Russia's Vladimir Putin that the international situation was gripped by chaos but that Beijing's strategic partnership with Moscow was a force for stability amid the most significant changes seen in a century.

Indian prime minister Narendra Modi and Chinese president Xi Jinping held their first formal meeting in five years after a violent border confrontation between the two countries threw bilateral relations into a tailspin.