United States President Donald Trump says he has had “very good talks” with Iran over the past 24 hours and it is “very possible that we will make a deal”, as Tehran reviews a US peace proposal that sources said would formally end the war.

Signalling progress in the ongoing talks between the two sides, Trump on Wednesday also said Iran should suspend its nuclear programme and reopen the Strait of Hormuz, threatening to resume bombardment if negotiations fall apart.

“Look, this is very simple. Iran cannot have a nuclear weapon because as tough as they are, we want to keep them alive. We want to keep all of you alive,” he told reporters at the White House.

In an interview with US media outlet PBS, Trump also said he was optimistic about reaching an agreement with Iran before his scheduled trip to China next week.

“I think it’s got a very good chance of ending, and if it doesn’t end, we have to go back to bombing the hell out of them,” he said.

Meanwhile, Iran’s Foreign Ministry spokesman Esmaeil Baghaei played down reports suggesting an agreement with the US was close, calling them exaggerated.

He said Tehran had not yet issued a formal response to the latest US proposal, but is continuing to exchange diplomatic messages via mediator Pakistan.

Trump has repeatedly played up the prospect of an agreement that would end the US-Israel war on Iran that started on February 28, so far without success. The two sides remain at odds over a variety of difficult issues, such as Iran’s nuclear ambitions and its control of the Strait of Hormuz, which before the war handled one-fifth ‌of the world’s oil and gas supply.

A Pakistani source and another source briefed on the mediation told the Reuters news agency that an agreement was close on a one-page memorandum that would formally end the conflict. That would kick off discussions to unblock shipping through the strait, lift US sanctions on Iran, and set curbs on Iran’s nuclear programme, the sources told the agency.

It was unclear how the memorandum differs from a 14-point plan proposed by Iran last week.

Iran’s semiofficial Tasnim news agency, citing an unnamed source, said the US proposal contained some unacceptable provisions, without specifying which ones.

Lawmaker Ebrahim Rezaei, a spokesperson for the Iranian Parliament’s Foreign Policy and National Security Committee, described the text as “more of an American wish list than a reality”.

“The Americans will not gain anything in a war they are losing that ⁠they have not gained in face-to-face negotiations,” he wrote on social media.

US State Department spokesman Tommy Pigott told Al Jazeera that Trump remained “clear-eyed” about the temporary short-term disruptions caused by Iran’s effective closure of the Strait of Hormuz, but that Washington can’t “normalise a country being able to determine who is allowed to use an international waterway”.

“I am certainly not going to preview or predict the actions of what the president may decide in the future, but the president has been clear from the very beginning that he prefers a diplomatic solution… But make no mistake that President Trump means what he says when he says the Iranian regime can never be allowed to obtain a nuclear weapon,” he said.

Israeli Prime Minister Benjamin Netanyahu said he would speak with Trump later on Wednesday about the ongoing negotiations with Iran, adding that they had both agreed that all enriched uranium must be removed from Iran to prevent it from developing a nuclear bomb.

Iran has steadfastly refused to give up its enriched uranium, which it insists is not for making a nuclear weapon.

Meanwhile, US military forces operating in the Gulf of Oman said they had disabled an Iranian-flagged oil tanker after it allegedly failed to comply with warnings, US Central Command (CENTCOM) announced.

CENTCOM said in a statement that the vessel – identified as the M/T Hasna – was observed transiting international waters en route to an Iranian port on the Gulf of Oman at approximately 14:00 GMT on Wednesday.

US forces issued “multiple warnings” to the tanker, informing its crew that the vessel was in violation of the blockade, the command said. The US blockade against ships attempting to enter or depart Iranian ports remains “in full effect”, it reiterated.

Trump late on Tuesday announced a pause in “Project Freedom”, a US military operation to guide stranded commercial ships through the Strait of Hormuz – after only a day – citing a chance to seal a deal to end the war.

Trump wrote on social media that the surprise decision to halt the mission came after requests from “mediator Pakistan and other countries”, saying “Great Progress has been made toward a Complete and Final Agreement” with Tehran.