President Donald Trump reportedly threatened Iraq with harsh sanctions Sunday after Iraqi lawmakers voted for a measure expelling U.S. troops from the country. Speaking to reporters on Air Force One, Trump said: "If they do ask us to leave, if we don't do it in a very friendly basis, we will charge them sanctions like they've never seen before ever. It'll make Iranian sanctions look somewhat tame," according to CNBC . Trump also said Iraq would have to pay back the U.S. for billions of dollars spent on an air base. "We're not leaving unless they pay us back for it," he said, according to CNBC. Trump also doubled down on his Twitter threat to target Iranian cultural sites -- a potential war crime -- if Iran strikes back against the U.S. in response to last week's airstrike that killed one of its top generals. "They're allowed to use roadside bombs and blow up our people," Trump said on Air Force One, according to the New York Times . "And we're not allowed to touch their cultural site? It doesn't work that way."