At the start of a four-day visit to India for meetings with Indian, Australian and Japanese officials, Mr Rubio said he hopes there will be good news in the coming hours.

He said the negotiations have succeeded in one of Mr Trump’s main aims – ensuring “a world that no longer has to be in fear or worry about an Iranian nuclear weapon”.

Mr Trump said on Saturday he had spoken with leaders from Saudi Arabia, the United Arab Emirates, Qatar, Pakistan, Turkey, Egypt, Jordan and Bahrain, and separately with Israel.

“Final aspects and details of the Deal are currently being discussed, and will be announced shortly,” he said on social media, with no details.

The announcement capped a week in which the US weighed a new round of attacks on the Islamic Republic that would break a fragile ceasefire.

The potential deal will include Iran’s commitment that it will not pursue a nuclear weapon, and Tehran agreed to give up its stockpile of highly enriched uranium, according to two regional officials.

One official, with direct knowledge of the negotiations, said how Iran will give up its highly enriched uranium is a subject of further negotiations over the course of a 60-day period.

It is highly likely that a part of the amount will be diluted, while the rest will be transferred to a third country, potentially Russia, he said.

Iran has 440.9 kilograms (972 pounds) of uranium that is enriched up to 60% purity, a short, technical step from weapons-grade levels of 90%, according to the International Atomic Energy Agency.

The Strait of Hormuz will be gradually open in parallel with the US ending its blockade of Iran’s ports, said the official.

The US will also allow Iran to sell its oil through sanctions waivers, said the second official who has been briefed on the negotiations. Sanctions relief and release of Iran’s frozen funds will be negotiated during the 60-day timeframe, he said.

Both officials said the draft deal includes an end of the war between Israel and Hezbollah, as well as a commitment of not interfering in the domestic affairs of countries in the region.

Twelve weeks have passed since the US and Israel attacked Iran on February 28, killing top Iranian officials including its supreme leader and interrupting nuclear talks between the US and Iran for the second time in less than a year.

Iran fired at Israel and at neighbours hosting US forces, shaking Gulf nations that had considered themselves safe havens in a tough region.

A ceasefire has held since April 7. But Iran’s decision to effectively close the Strait of Hormuz for ships carrying regional oil, natural gas and other critical supplies has been a focal point of global concern and economic pain.