President Trump told reporters aboard Air Force One Sunday the U.S. wouldn't leave the joint U.S. air base with Iraq "unless they pay us back," and he doubled down on his threat to target 52 Iranian sites.

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."

Why it matters: Iraq's parliament passed a resolution earlier Sunday urging the government to expel U.S. troops from the country over the killing of Iranian Gen. Qasem Soleimani and the leader of an Iraqi militia on its soil.

Per Axios' Dave Lawler, the vote does not formally revoke Iraq's invitation for the U.S. to have a presence in the country, but it is a step along that path.

Trump's threat to attack cultural sites could be considered a war crime under the 1954 Hague treaty.

What he's saying: "We've spent a lot of money in Iraq," Trump told reporters, according to a pool report.

"Iraq, was the worst decision, going into the Middle East was the worst decision ever made in the history of our country ... We're not leaving unless they pay us back for it," he said of the joint air base.

On the targeting of cultural sites, Trump said, "They’re allowed to kill our people. They’re allowed to torture and maim our people; they’re allowed to use roadside bombs and blow up our people. And we’re not allowed to touch their cultural site? It doesn’t work that way."

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