North Korean leader Kim Jong Un met with the leader of a Russian delegation in Pyongyang and called for deepening trade, economic and scientific ties between the two countries, state media reported Tuesday.

North Korea ratified a major defence pact with Russia on Tuesday, outlining mutual military aid and requiring both countries to provide each other with immediate military assistance if attacked. Russia had already completed its side of the ratification last week after the pact was signed by Russian President Vladimir Putin and North Korean leader Kim Jong Un.

The number of North Korean troops stationed inside Russia could grow to 100,000, Ukrainian President Volodymyr Zelenskiy said on Tuesday. Kyiv and its Western allies say North Korea has supplied Russia with weaponry and troops to bolster its full-scale invasion of Ukraine.