“At this moment, I’m not satisfied with what they’re offering,” Trump told reporters at the White House.

The president’s remarks came after Iranian state media reported that Tehran had delivered the text of a talks proposal to mediator Pakistan on Thursday evening.

The war, launched by the United States and Israel with a vast wave of surprise strikes on February 28, has been on hold since April 8 with a ceasefire. But only one failed round of direct talks has taken place between Iranian and US representatives.

Meanwhile Iran has maintained its stranglehold on the Strait of Hormuz, cutting off vast amounts of oil, gas and fertilizer from the world economy, while the US has imposed a counterblockade on Iranian ports.

Asked why he was unsatisfied with the Iranian offer, Trump said: “They’re asking for things that I can’t agree.” He gave no details.

Trump said Iran had “made strides” in negotiations, but added that there was “tremendous discord” in the Islamic Republic’s leadership and warned: “I’m not sure if they ever get there.”

Trump was asked what he would do if there was no deal but refused to say whether he would launch more strikes.

“Do we want to go and just blast the hell out of them and finish them forever – or do we want to try and make a deal? I mean, those are the options,” he said.

Trump added that he would “prefer not” to launch a huge offensive but added: “That’s the option: do we want to go in there heavy and just blast them away or do we want to do something?”

He was also asked about blowing past the 60-day deadline set out in the War Powers Act for getting congressional approval for the war, and claimed that the notion that he would need approval was “totally unconstitutional.”

“Also, we had a ceasefire, so that gives you additional time, but no other country has done it,” he said. “We’re in the midst of a big victory. This is a victory like we haven’t had since Venezuela.” He meant the US ouster of Nicolas Maduro in January.