An Iranian proposal so far rejected by US President Donald Trump would open shipping in the Strait of Hormuz and end the US blockade of Iran while leaving talks ​on Iran’s nuclear programme for later, a senior Iranian official said on Saturday.

Four ‌weeks since the United States and Israel suspended their bombing campaign against Iran, no deal has been reached to end a war that has caused the biggest disruption ever to global energy supplies.

Iran has been blocking ​nearly all shipping from the Gulf apart from its own for more than two ​months. Last month the US imposed its own blockade of ships from ⁠Iranian ports.

Trump said on Friday he was “not satisfied” with Iran’s latest proposal, without spelling out ​which elements he opposes.

“They’re asking for things that I can’t agree to,” he ​told reporters at the White House.

Washington has repeatedly said it will not end the war without a deal that prevents Iran from ever obtaining a nuclear weapon, the primary aim Trump cited when he launched the ​strikes in February in the midst of nuclear talks. Iran says its nuclear programme is ​peaceful.

Speaking on condition of anonymity to discuss confidential diplomacy, the senior Iranian official said Tehran believed its ‌latest proposal ⁠to shelve nuclear talks for a later stage was a significant shift aimed at facilitating an agreement.

Under the proposal, the war would end with a guarantee that Israel and the United States would not attack again. Iran would open the strait, and the United States would ​lift its blockade.

Future talks ​would then be ⁠held on curbs to Iran’s nuclear programme in return for the lifting of sanctions, with Iran demanding Washington recognise its right to enrich ​uranium for peaceful purposes, even if it agrees to suspend it.

“Under this ​framework, negotiations ⁠over the more complicated nuclear issue have been moved to the final stage to create a more conducive atmosphere,” the official said.

Reuters and other news organisations already reported over the past week ⁠that Tehran ​was proposing to reopen the strait before nuclear issues ​were resolved; the official confirmed that this new timeline had now been spelt out in a formal proposal conveyed ​to the United States through mediators.