President Donald Trump doubled down Sunday on his belief that the United States military has the right to target Iranian cultural sites, dismissing concerns from the public and even from his own administration that he would be committing a war crime by doing so.

The threat comes as the president continues escalating tensions with Iran after authorizing a U.S. airstrike that killed a top Iranian general at an airport Friday in Baghdad. The assassination of Gen. Qassem Soleimani has led to fury from Iran and unhinged threats of war from Trump.

“They’re allowed to kill our people,” Trump told White House reporters Sunday on Air Force One. “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.”

Trump defends his cultural site threat: “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.” — Zeke Miller (@ZekeJMiller) January 6, 2020

The remarks echo Trump’s comments a day earlier, when he tweeted that he will attack 52 Iranian sites if the country’s government retaliates against the U.S. over Soleimani’s death. The president did not say which places the U.S. might strike, but alleged that some of those sites are cultural sites. The number of sites is the same as the number of Americans held hostage during the Iranian Revolution takeover of the U.S. Embassy in Tehran in 1979.

Many responded to his tweet by reminding him that attacking cultural sites and places of worship are war crimes under international law. The U.S. is a party to the 1954 Hague Convention, a treaty on international law that protect cultural property in the event of armed conflict. Signatories adopted the treaty because “damage to cultural property belonging to any people ever means damage to the cultural heritage of all mankind.”

Iran’s foreign minister, Mohammad Javad Zarif, hit back at Trump by comparing his threats to that of terrorists who have also destroyed cultural sites.

“A reminder to those hallucinating about emulating ISIS war crimes by targeting our cultural heritage: Through MILLENNIA of history, barbarians have come and ravaged our cities, razed our monuments and burnt out libraries,” Zarif tweeted Sunday morning in response to Trump’s initial comments. “Where are they now? We’re still here, & standing tall.”

A reminder to those hallucinating about emulating ISIS war crimes by targeting our cultural heritage:

Through MILLENNIA of history, barbarians have come and ravaged our cities, razed our monuments and burnt our libraries.



Where are they now?



We’re still here, & standing tall. — Javad Zarif (@JZarif) January 5, 2020

Two senior U.S. officials on Sunday told CNN that there was widespread opposition within the Trump administration to targeting cultural sites in Iran if the U.S. retaliates. Secretary of State Mike Pompeo told several Sunday shows that the U.S. will launch retaliatory strikes against Iran if attacked, but dodged questions about whether those strikes would hit cultural sites.

“We’ll behave lawfully. We’ll behave inside the system,” Pompeo told George Stephanopoulos on ABC’s “This Week.”

NEW: @GStephanopoulos presses Sec. of State Mike Pomepo on Trump's tweet warning cultural sites could be targeted if Iran retaliates: "Why is the president threatening Iran with war crimes?"



Pompeo: "We'll behave lawfully. We'll behave inside the system." https://t.co/YGK7RRbV73 pic.twitter.com/Qg2s6B6lGE — ABC News Politics (@ABCPolitics) January 5, 2020

Soleimani’s death also marks a massive shift in Washington’s relationship with Iran. The country’s leaders have vowed to retaliate against the U.S. over the assassination, and Iran on Sunday officially pulled out of the 2015 nuclear deal that prevented them from amassing enough material to create an atomic weapon. Trump withdrew the U.S. from the deal in 2018 and increased sanctions on Tehran, which escalated tensions that eventually resulted in Soleimani’s assassination.

The Trump administration has claimed that the airstrike on Soleimani was necessary because he was planning an imminent attack, though the White House has not made any details about the supposed attack public.

Iraq’s parliament voted Sunday to expel American forces from the country in response to the U.S. airstrike on Soleimani. More than 5,000 U.S. troops are still on the ground in Iraq 17 years after the war began.

Trump said the U.S. will not leave Iraq without being paid for its military investments in the country. He then said that if soldiers do have to leave, the president would put economic sanctions on Baghdad.

“We will charge them sanctions like they’ve never seen before ever. It’ll make Iranian sanctions look somewhat tame,” he told reporters Sunday. “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.”