US President Donald Trump says Iranian leaks of details of an alleged deal to end the war have "nothing to do with the terms that were agreed to" and "bears no relation to the truth".
Trump said they were "very dishonorable people to deal with" and should "get their act together, and FAST!"
The reaction came as Iranian media reported purported details that included much of what Tehran has been publicly demanding and the US rejecting. US officials have also mentioned terms that Iran has consistently rejected.
Iran's Foreign Minister Seyed Abbas Araghchi said a deal had "never been closer" and urged the media to "refrain from entering speculation about its content".
Trump has also repeatedly talked up the prospects of a deal to end the war that began with wide-ranging US and Israeli strikes across Iran on 28 February.
Iran responded with attacks on Israel and US-allied states in the Gulf - as well as effectively closing the Strait of Hormuz, a key shipping route for the world's oil and liquefied natural gas.
Despite having agreed a ceasefire in April, the US and Iran have exchanged intermittent fire, including two rounds of tit-for-tat strikes this week.
On Thursday, the US president had threatened new attacks only to state later that he had cancelled them because negotiators had "just made a great settlement" with Iran - a deal that was likely be to signed imminently. It prompted Iran to say reports of an agreement were "speculative" and "nothing had been finalised".
On Friday, Iranian media published what they described as terms of an agreement. The reported details included the lifting of a US naval blockade and "at least $300bn (£223bn)" to address the damage caused by the US and Israeli strikes on Iran.
Israel is not involved in the talks which have been mostly mediated by Pakistan and are meant to lead to an extension of the ceasefire and the start of negotiations on key issues, including Iran's nuclear programme. For decades, Iran has been accused by Western countries of trying to build a nuclear weapon. It has denied the accusations saying its programme is for peaceful purposes - to generate electricity and for research purposes.
Iran's Mehr news agency which published the alleged contents of the deal said Iran wanted a final agreement to be endorsed by a UN Security Council resolution.
"The final agreement shall be limited to issues concerning the future of enriched materials and enrichment activities, sanctions relief, and the programme for rebuilding Iran's economy," it said.
It added that "final negotiations shall not begin until half of Iran's frozen assets have been released, Iranian oil sanctions have been suspended, and the naval blockade has been lifted".
The list of issues included typical Iranian demands, including the end of the Israeli conflict with Iran-backed Hezbollah in Lebanon.
From the US perspective, a senior administrative official told the BBC the Iran deal included the expectation that nuclear material was destroyed and removed and the nuclear program dismantled.
The official said that none of Iran's money would released until the Iranians had met US demands, the Strait of Hormuz would be opened and Iran would be expected not to fund terrorist groups - a reference to Hezbollah and other Iranian proxies across the Middle East.
US Vice-President JD Vance added his voice later, saying he had noticed "a couple of bizarre things in the reporting over the last few hours".
"Iranians are not receiving any cash, and no funds are being released for simply signing a deal or attending a meeting," Vance said in a post on X.
He added that the deal "is structured to ensure that the US and its allies concerns are prioritized, and that if the Islamic Republic of Iran meets its obligations, then economic benefits will flow to them and to the entire region".
