The shrine of Iran's revolutionary founder Ayatollah Khomeini, just outside of Tehran, Iran, has become a potential U.S. military target. President Donald Trump insisted Sunday that Iranian cultural sites were fair game for the U.S. military should Iran strike any U.S. person or target in retaliation for a U.S. strike in Baghdad that killed a top Iranian official.

WASHINGTON — President Donald Trump insisted Sunday that Iranian cultural sites were fair game for the U.S. military, dismissing concerns within his own administration that doing so would constitute a war crime under international law. He also warned Iraq that the U.S. would levy punishing sanctions if it expelled American troops in retaliation for a U.S. strike in Baghdad that killed a top Iranian official.

Trump’s comments came amid escalating tensions in the Middle East following last week’s strike on Gen. Qassem Soleimani, the head of Iran’s elite Quds force. Iran has vowed to retaliate and Iraq’s parliament responded by voting Sunday to oust U.S. troops based in the country.

“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 sites? It doesn’t work that way,” Trump told reporters aboard Air Force One as he returned to Washington from a holiday stay at his Florida estate.

Trump cast his response to Parliament’s decision in monetary terms, saying the U.S. expected to be paid for its military investments in Iraq before leaving the country and threatening economic sanctions if the U.S. is not treated properly.

“We have a very extraordinarily expensive air base that’s there. It cost billions of dollars to build. Long before my time. We’re not leaving unless they pay us back for it,” he told reporters.

“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,” he said. “If there’s any hostility, that they do anything we think is inappropriate, we are going to put sanctions on Iraq, very big sanctions on Iraq.”

He added: “We’re not leaving until they pay us back for it.”

Earlier Sunday, Secretary of State Mike Pompeo said the U.S. military may strike more Iranian leaders if the Islamic Republic retaliates. His comments came as other repercussions from the attack played out: the U.S. military coalition in Baghdad suspended training of Iraqi forces to concentrate on defending coalition troops; and in Beirut, the Lebanese Hezbollah chief said U.S. forces throughout the Mideast are fair targets for retaliation.

In Tehran, Iranian state television reported that the country will no longer abide by any limits of the 2015 nuclear deal it signed with the United States and other world powers. Trump withdrew the U.S. from the deal in 2018 and stepped up economic sanctions on Tehran — actions that accelerated a cycle of hostilities leading to the Soleimani killing.

The State Department had no immediate comment on Iran reportedly abandoning the nuclear deal, a move that holds the prospect of Iran accelerating its production of materials for a nuclear weapon.

Trump had issued warnings to Iran by tweet Sunday afternoon. “These Media Posts will serve as notification to the United States Congress that should Iran strike any U.S. person or target, the United States will quickly & fully strike back, & perhaps in a disproportionate manner,” he wrote. “Such legal notice is not required, but is given nevertheless!”

That tweet also appeared to serve as a warning to Congress — that Trump would respond quickly to any attack and without first gaining the approval of lawmakers. Democrats in Congress have complained that Trump’s order to kill Soleimani took place without first consulting with or informing top lawmakers, noting that Congress still holds sole power to declare war. Trump did meet the 48-hour deadline required by the War Powers Act to notify Congress of the deadly drone strike, though the document provided Saturday was entirely classified and no public version was released.

The White House faced a barrage of questions about the killing’s legality. Pompeo said the administration would have been “culpably negligent” in its duty to protect the United States if it had not killed Soleimani, although he did not provide evidence for his previous claims that Soleimani was plotting imminent attacks on Americans. Instead of arguing that an attack had been imminent, he said it was inevitable.