US Defence Secretary Mark Esper on Monday strongly suggested that the US military would not violate the laws of armed conflict by striking Iranian cultural sites, a move threatened by President Donald Trump.

On being asked by media that whether he was willing to target cultural sites, Esper said, “We will follow the laws of armed conflict”.

“That’s the laws of armed conflict.” He did not elaborate”, Esper added.

The split between the president and his Pentagon chief came amid heightened tensions with Tehran following a US drone strike that killed Gen. Qassem Soleimani, the head of Iran’s elite Quds Force. Trump had twice warned that he would hit Iranian cultural sites if Tehran retaliates against the US.

On Saturday, Trump took to Twitter and said, “We have targeted 52 Iranian sites (representing the 52 American hostages taken by Iran many years ago), 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”.

The Pentagon has long had a list of potential targets both inside Iran as well as those associated with Iran throughout the Middle East. Those targets and war plans are routinely updated, including during the recent uptick in hostilities.

Officials won’t discuss the list, but it is certain to include an array of Iranian military sites and capabilities, including missile, air defense and command and control locations.

On Saturday, Trump came up with his defence that his order to kill General Qasem Soleimani, the head of Iran’s Islamic Revolutionary Guard Corps’ (IRGC) elite Quds Force, claiming that the deceased had contributed to “terrorist plots as far away as New Delhi and London”.

Iran had termed the US action of “international terrorism” as “extremely dangerous and a foolish escalation”.

General Qasem Soleimani was among the eight people killed in a rocket attack by the US on Baghdad international airport.

Ahead of Esper’s comments, other administration officials tried to make clear that the US would follow the law without directly contradicting the president.

On Sunday, Secretary of State Mike Pompeo said that any US military strikes inside Iran would be legal.

“We’ll behave inside the system,” Pompeo further said.

“We always have and we always will”, he added.