The Pentagon sought to distance itself from the president’s comments, saying the US will ‘follow the laws of armed conflict’

Donald Trump has defended his threat to target Iranian cultural sites – widely seen as a war crime – if Tehran retaliates for the killing of General Qassem Suleimani.

On bellicose form, the US president also lashed out at Iraq following its parliament’s demand for American troops to be expelled from that country, and vowed to respond with crippling sanctions.

Play Video 0:54 Qassem Suleimani's daughter warns US of 'dark days' ahead - video

Trump’s comments suggest he was making no idle threat when, on Saturday night, he tweeted that the US has “targeted 52 Iranian sites ... some at a very high level & important to Iran & Iranian culture, and those targets, and Iran itself, WILL BE HIT VERY FAST AND VERY HARD.”

Speaking to reporters aboard Air Force One a day later, he sought to offer a justification. “They’re allowed to kill our people,” Trump said, according to a pool report. “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.”

Targeting cultural sites is prohibited by international conventions signed in Geneva and at the Hague. In 2017, the United Nations security council passed unanimously a resolution condemning the destruction of heritage sites. The action previewed by Trump would almost certainly involve the deaths of civilians.

The Pentagon, however, sought to distance itself from Trump’s threats, with defense secretary Mark Esper saying on Monday that the US will “follow the laws of armed conflict”, including those that ruled out targeting cultural sites.

Esper’s public comments reflected the private concerns of other defense and military officials, who cited legal prohibitions on attacks on civilian, cultural and religious sites, except under certain, threatening circumstances.

Trump’s statements come after secretary of state Mike Pompeo defended the assertion that the drone strike against Suleimani in Baghdad prevented an imminent attack on US interests. “We would have been culpably negligent had we not taken this action,” he told NBC’s Meet the Press on Sunday. When host Chuck Todd asked if retaliation against US citizens should now be expected, Pompeo admitted: “It may be that there’s a little noise here in the interim.”

US-Iran tensions are escalating following last Friday’s drone strike – ordered by Trump without congressional authorisation – in Iraq that killed Suleimani, commander of Iran’s Islamic Revolutionary Guard Corps Quds Force.

Diplomacy over Iran is still possible – if only to avoid an all-out war Read more

On Monday morning in Tehran, the supreme leader, Ayatollah Khamenei presided over prayers for the slain general, and Suleimani’s daughter Zeinab told a huge crowd at his funeral ceremony that the US and its ally Israel faced a “dark day” for his death.

“Crazy Trump, don’t think that everything is over with my father’s martyrdom,” Zeinab Suleimani said in an address broadcast on state television. “The families of US soldiers in the Middle East will spend their days waiting for death of their children.”

Facebook Twitter Pinterest Ayatollah Khamenei, centre, leads a prayer in Tehran over the coffins of Qassem Suleimani and others killed in a US drone strike on Friday. Photograph: AP

Before the ceremony, mourners had packed the streets around Tehran university, chanting “Death to America” and “Death to Israel”. One man held up a placard reading “hard–revenge”.

Profile Who was Qassem Suleimani? Show Hide Qassem Suleimani, killed by a US drone strike in Baghdad, had become well known among Iranians and was sometimes discussed as a future president. Many considered Suleimani to have been the second most powerful person in Iran, behind supreme leader of Iran Ali Khamenei, but arguably ahead of President Hassan Rouhani. He was commander of the Quds Force, the elite, external wing of the Iran’s Islamic Revolutionary Guard Corps, which the Trump administration designated as a terror organisation in April last year. He was born in Rabor, a city in eastern Iran, and forced to travel to a neighbouring city at age 13 and work to pay his father’s debts to the government of the Shah. By the time the monarch fell in 1979, Suleimani was committed to the clerical rule of Ayatollah Ruhollah Khomeini, and joined the Revolutionary Guards, the paramilitary force established to prevent a coup against the newly declared Islamic Republic. Within two years, he was sent to the front to fight in the war against the invading Iraqi army. He quickly distinguished himself, especially for daring reconnaissance missions behind Iraqi lines, and the war also gave him his first contact with foreign militias of the kind he would wield to devastating effect in the decades to come. By the the time the Iraq government fell in 2003, Suleimani was the head of the Quds force and blamed for sponsoring the Shia militias who killed thousands of civilian Iraqis and coalition troops. As fighting raged on Iraq’s streets, Suleimani fought a shadow war with the US for leverage over the new Iraqi leadership. Once described by American commander David Petraeus as ‘a truly evil figure’, Suleimani was instrumental in crushing street protests in Iran in 2009. In recent months outbreaks of popular dissent in Lebanon, Iraq and Iran were again putting pressure on the crescent of influence he had spent the past two decades building. Violent crackdowns on the protests in Baghdad were blamed on militias under his influence.

Eighteen months before his death, Suleimani had issued Donald Trump a public warning, wagging his finger and dressed in olive fatigues. “You will start the war but we will end it.” Michael Safi Photograph: Mehdi Ghasemi/AFP

The ceremony followed a turbulent weekend that saw the Iraqi parliament pass a resolution calling on the government to expel US troops, of which about 5,000 remain, most in an advisory capacity. On Sunday, Iran’s government said the country would no longer observe limitations on uranium enrichment, stockpiles of enriched uranium or nuclear research and development. The statement noted that the steps could be reversed if Washington lifted its sanctions on Tehran.

Facebook Twitter Pinterest Iranian general Qassem Suleimani. Photograph: Anadolu Agency/Getty Images

On Sunday, Human Rights Watch condemned the president’s latest threat to Iran’s culture sites: “President Trump should publicly reverse his threats against Iran’s cultural property and make clear that he will not authorise nor order war crimes,” said Andrea Prasow, its acting Washington director. “The US Defense Department should publicly reaffirm its commitment to abide by the laws of war and comply only with lawful military orders.”

She added: “Trump’s threat to attack Iran’s cultural heritage shows his callous disregard for the global rule of law. Whether refusing to condemn the brutal murder of Saudi dissident Jamal Khashoggi or pardoning convicted war criminals, Trump has shown little respect for human rights as part of US foreign policy.”

House Speaker Nancy Pelosi called Trump’s drone strike “provocative and disproportionate” and said legislation would be introduced this week to halt the president’s military actions regarding Iran unless Congress is involved.

She told Democrats: “We are concerned that the administration took this action without the consultation of Congress and without respect for Congress’s war powers granted to it by the Constitution.”

Trump spoke to reporters on Sunday as he flew back to Washington from another eventful holiday at his Mar-a-Lago estate in Palm Beach, Florida. He showed no hint of regret. Asked about vows of vengeance from Iran, the president said simply: “If it happens it happens. If they do anything, there will be major retaliation.”

He also turned his ire on Iraq after that country’s parliament passed a resolution calling on the Iraqi government to expel US troops. “We have a very extraordinarily expensive air base that’s there,” he said. “It cost billions of dollars to build. Long before my time. We’re not leaving unless they pay us back for it.

“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.”

Trump’s remarks look set to trigger another political firestorm amid concerns that he has not considered the consequences of the strike against Suleimani and may even be seeking to distract from his upcoming impeachment trial.

Brett McGurk, the former US presidential envoy to the global coalition to counter Isis, tweeted: “Trump’s comments tonight regarding Iran and Iraq are not only unacceptable, they’re unAmerican. American military forces adhere to international law. They don’t attack cultural sites. And they’re not mercenaries. Reckless and unprecedented words from a commander-in-chief.”

The Associated Press contributed reporting