US President Donald Trump on Monday demanded that Iran pay compensation for the deaths of people he said it had killed in wars, attacks and protests, raising tensions with Tehran as hopes faded for an imminent agreement to reopen the Strait of Hormuz.

Trump said he was responding to Iran’s earlier demand that Washington meet conditions including compensation for damage caused during the more than five months since the US and Israel launched strikes on Iranian territory.

“I am likewise demanding compensation from Iran, for all of the people that they have killed and gravely wounded with their roadside bombs and many conflicts, for which they are famous,” Trump wrote on his Truth Social platform.

The new US demand had not been raised in previous talks. Trump said it would be included in all future negotiations with Iran and would include payments to the families of hundreds of thousands of protesters he said had been killed by Iranian authorities.

He also said Iran should compensate “families of those killed on the USS Cole”, referring to the October 12, 2000 attack on the US Navy vessel in Yemen that killed 17 American sailors. The attack was attributed to al Qaeda, rather than Iran.

Iran had earlier said it was close to reaching a final agreement with Oman on new shipping lanes through the Strait of Hormuz. Tehran said, however, that the US would first have to meet conditions including compensation, an end to sanctions and an end to military threats before the waterway could be reopened.

The strait, through which around a fifth of global oil and liquefied natural gas supplies passed before the conflict, has been effectively blocked since the US and Israeli attacks on Iran began on February 28.

Oil prices rose sharply after Iranian Foreign Ministry spokesman Esmaeil Baghaei outlined Tehran’s conditions, with Brent crude trading more than 4 per cent higher. Dutch and British front month gas prices also rose by more than 10 per cent.

Trump has said the US attacks were intended to prevent Iran from developing nuclear weapons and reduce its ability to threaten countries in the region. He is also under pressure to end a conflict that has proved unpopular in the US ahead of November’s midterm elections.

Washington and Tehran agreed to a ceasefire in June, but the US imposed a new blockade on Iranian shipping in the Gulf in July. Iran said the move violated the truce, which had already broken down.

Iranian attacks on shipping around the Strait of Hormuz have coincided with increased attacks by the Houthis, an Iran-aligned group based in Yemen, against vessels around the Red Sea and Gulf of Aden.

The Houthis declared a naval blockade against Saudi Arabia in the Red Sea last month, saying it was in response to what they described as a Saudi siege in Yemen. Riyadh denied the allegation.

Fighting has also intensified between the Houthis and Yemeni government forces. Yemen’s military said on Monday that seven people, including military personnel and civilians, were killed in a Houthi attack on the Red Sea port city of Mocha.

The military said air defences intercepted and destroyed 11 Houthi drones involved in the attack.