Donald Trump has accused Iran of trying to stall on making a peace agreement by running down the clock before November’s US midterm elections in the hope of getting better terms.

“They thought they were going to out-wait me, you know, ‘We’ll out wait him, he’s got the midterms,” the US president told a meeting of his cabinet at the White House on Wednesday.

He insisted the approach – supposedly aimed at ratcheting up pressure on the US and global economies by keeping the strategically vital strait of Hormuz closed – would fail, and claimed that Iran “wants very much to make a deal”.

“I don’t care about the midterms, look what happened last night,” Trump said, an apparent reference to the triumph of Ken Paxton, who he had endorsed, over the sitting Republican senator John Cornyn in the Republican Senate primary.

Trump said the Iranian economy was in freefall, suggesting that made it imperative for Iran to compromise. “They have 250% inflation, their money has no value, their whole economic system is broken down.”

His comments, at the 12th cabinet meeting of Trump’s second term, came as talks aimed at ending the near-three-month conflict are said to be at a crucial stage. Current attempts to reach a deal had so far failed, he claimed, because “we’re not satisfied with it”.

“But we will be,” the president added. “Either that, or we will just have to finish the job”.

Asked if he would agree to a short-term deal that allowed Iran and Oman to be in control of the strait of Hormuz, Trump replied: “The strait is going to be open to everybody. Nobody is going to control it. We’ll watch over it , but nobody is going to control it. That’s part of the negotiation that we have. They would like to control it. It’s international waters and Oman will behave just like everybody else, or we will have to blow them up.”

He said one consequence of a putative deal under discussion is that the strait – which was a conduit for 20% of the world’s energy supplies before the war – would open immediately.

At one one stage, Trump appeared to contradict himself after renewing his call on Arab allies including Saudi Arabia and Qatar to sign the Abraham accords granting full diplomatic recognition of Israel.

“I think those countries owe to us … I don’t think we should make a deal if they don’t sign,” he said.

But he retreated when asked if the Iran agreement was contingent on more countries joining the accords – which were signed by the United Arab Emirates, Bahrain, Sudan and Morocco during his first presidency – saying: “I don’t want to say that. I’m not going to give you what’s contingent.”

He also claimed to have brought about regime change in Iran through the assassinations of a generation of the country’s leaders, including the supreme leader, Ayatollah Ali Khamenei, its most powerful figure – even though he has been succeeded by his son, Mojtaba Khamenei, who is considered to be more hardline than his father.

“We didn’t set out for regime change, but … we are dealing with a completely different group of people than we were at the beginning,” Trump said. “I actually find them to be smarter. One regime is gone, another regime is gone, we are dealing with the third.”

The gathering had originally been scheduled to take place in the bucolic setting of Camp David, the presidential retreat that had previously been the site of sensitive Middle East negotiations, including the historic Israeli-Egyptian peace accords.

But Trump switched it back to its more accustomed White House setting, citing adverse weather forecasts.

The initial decision to stage it at Camp David had raised eyebrows, given that Trump had visited the presidential retreat deep in the Maryland countryside, 62 miles north-west of Washington, much less frequently than most of his predecessors.

The gathering comes as Trump’s approval ratings sink and economic pessimism rises amid the war with Iran.

Trump announced at the weekend that a deal to end hostilities was close at hand, although the US on Monday struck Iranian targets, reportedly killing four members of the Islamic Revolutionary Guard Corps. Negotiations, nevertheless, were said to be continuing.

Trump – who said last Saturday that an agreement with Iran “had been largely negotiated” – has sent confusing signals on peace prospects after a largely negative reaction from US rightwing circles and anti-Tehran hawks.

In a social media post on Tuesday, he vented anger at media commentators who had depicted the emerging terms as favorable to Iran and a potential humiliation for him.

“If Iran surrenders … and admit their defeat to the great power and force of the magnificent USA, the Failing New York Times, the China Street Journal (WSJ!), Corrupt and now Irrelevant CNN, and all other members of the Fake News Media, will headline that Iran had a Masterful and Brilliant Victory over The United States of America,” he wrote.

Participants in the meeting included Tulsi Gabbard, who announced her forthcoming resignation as director of national intelligence last week. Gabbard attracted Trump’s ire last year after testifying to Congress that she believed Iran was not pursuing nuclear weapons, just months before US forces bombed the country’s uranium enrichment facilities.

Trump paid tribute to Gabbard on Wednesday, calling her “a terrific person” and prompting a round of applause from the rest of the cabinet. “Tulsi has worked tirelessly to restore trust and focus, with the intelligence community and they all respected her. They listened to her,” he said.