It would be foolish of the North Koreans to not test the effectiveness of their weapon systems in Ukraine so this should not be a surprise to anyone:

North Korea is using its support for Russia’s invasion of Ukraine to test weapons it could deploy against the South in a future conflict, Ukraine’s ambassador to Seoul said in a news report Sunday. Ukraine and South Korea share a common adversary, Ukrainian Ambassador to South Korea Dmytro Ponomarenko said in written remarks published by Yonhap News. South Korea “should not forget that Pyongyang also uses Ukrainian soil as a testing ground for its weaponry, which could be used in future possible standoff,” Ponomarenko said. Seoul “has no reason to hesitate in the development of full-scale military-technical cooperation” with Kyiv, he said. “It’s a matter of interest for both Kyiv and Seoul,” he added.
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