US and Iranian negotiators have reached an agreement on a 60-day memorandum of understanding to extend the ceasefire and launch negotiations on Iran's nuclear program, but President Trump has yet to give his final approval, Axios has reported quoting two US officials and a regional source involved in the mediation efforts.

Iran has also not confirmed its acceptance.

The signing of the MOU would be the most significant diplomatic breakthrough since the war started, but a final agreement that tackles Trump's nuclear demands would still require further intensive negotiations.

"This is an agreement to get everybody to the table. We will work out the details in the negotiations," one of the U.S. officials said

US officials said terms of the deal were mostly agreed to as of Tuesday, but both sides still needed approval from senior leadership.

The US officials claimed the Iranians later came back and said they had the necessary approvals and were prepared to sign. Iran has not confirmed that.

The US negotiators briefed Trump on the details of the final deal, but he did not immediately sign off. 

"The president relayed to the mediators that he wants a couple of days to think about it," a US official said.

The US officials said the 60-day MoU will state that shipping through the Strait of Hormuz will be "unrestricted." A US official said this means no tolls and no harassment and that Iran will have to remove all mines from the strait within 30 days.

The US naval blockade will also be lifted, but that will happen in proportion to the restoration of commercial shipping, a US official said. The US would also issue some sanctions waivers to allow Iran to sell oil freely.

The MOU will include an Iranian commitment not to pursue a nuclear weapon, the officials said. It will also state that the first issues to be negotiated during the 60-day window will be how to dispose of Iran's highly enriched uranium and how to address Iranian enrichment.

The US will commit to discuss sanctions relief and the release of frozen Iranian funds as part of the negotiations, said the report.