Iranian media have said that the United States had failed to make any concrete concessions in its latest response to Iran's proposed agenda for negotiations to end the war.
The Fars news agency said on Sunday that Washington had presented a five-point list, which included a demand for Iran to keep only one nuclear site in operation and transfer its stockpile of highly enriched uranium to the United States.
The US also refused to release "even 25 percent" of Iran's frozen assets abroad or pay any reparations for the damage inflicted on Iran during the war, which broke out on February 28, according to Fars.
The report added that the US had conditioned the cessation of hostilities on all fronts on the start of negotiations.
The Mehr news agency, meanwhile, said: "The United States, offering no tangible concessions, wants to obtain concessions that it failed to obtain during the war, which will lead to an impasse in the negotiations."
In its proposal, Iran had called for an end to the war on all fronts, including Israel's war on Lebanon, as well as a halt to the US naval blockade on Iranian ports in place since April 13.
It also called for lifting all US sanctions and the release of Iranian assets frozen abroad under longstanding US sanctions, according to the Iranian foreign ministry at a press conference last week.
Fars said the Iranian proposal had emphasised that Tehran would continue to manage the strategic Strait of Hormuz, a vital energy conduit which it has largely kept closed since the start of the war.
On Sunday, Iranian armed forces spokesperson Abolfazl Shekarchi warned US President Donald Trump against restarting attacks on Iran.
"The desperate American president should know that if his threats are carried out and Iran is attacked again, his country's resources and military will be confronted with unprecedented, offensive, surprising and tumultuous scenarios," he said, according to state television.
