U.S. plans to train Ukrainian servicemen in the use of Patriot missiles provides further proof of Washington’s participation in the Ukraine conflict, Russia’s ambassador to the United States said on Tuesday. "The decision of the U.S. defence department to organise a training course at Fort Sill in Oklahoma is yet another confirmation of Washington’s de facto participation in the Ukrainian conflict on the side of Kyiv’s Nazi criminals," Anatoly Antonov said in a statement posted by his embassy.