Former United States Secretary of State Mike Pompeo warned US President Donald Trump on Saturday against recognizing Crimea as Russian territory, claiming that would be "a mistake of epic proportions." "I get the frustration … I'm not naive about what’s physically possible in this moment, but that doesn’t mean one should go and say, ‘and we are giving up for all time," Pompeo, who served as the top US diplomat during Trump's first term, stated at the Black Sea Security Forum in Odessa. "This is one of the things I hope to communicate," he added.