Iran's chief negotiator on Tuesday issued an ultimatum to the United States to accept the conditions in Tehran's 14-point proposal for peace in the Middle East war or face "failure".
The defiant message came after US President Donald Trump rejected the latest counteroffer from Iran and said that a fragile ceasefire in place since April 8 was on "life support".
But Mohammad Bagher Ghalibaf said Washington had to accept Tehran's "rights" if it wanted to end more than two months of conflict, as peace talks remain deadlocked after an initial round failed to produce a breakthrough last month.
"There is no alternative but to accept the rights of the Iranian people as laid out in the 14-point proposal. Any other approach will be completely inconclusive; nothing but one failure after another," said Ghalibaf in a post on X.
"The longer they drag their feet, the more American taxpayers will pay for it."
Iran has refused to back down in its war with Washington, with military officials warning they are prepared to respond to any renewed US attack.
It has choked traffic through the key Strait of Hormuz trade route, rattling global markets and giving it vital leverage, while the US has imposed its own naval blockade on Iranian ports.
Details of the latest US proposal remain limited, though media reports say it involves a one-page memorandum of understanding aimed at ending the fighting and establishing a framework for negotiations on Iran's nuclear program.
Iran's foreign ministry said its response called for ending the war on all fronts, including Lebanon, halting the US naval blockade on Iranian ports and securing the release of Iranian assets frozen abroad under longstanding sanctions.
It did not elaborate on what Iran would offer in return.
On Tuesday, the spokesman for Iran's parliamentary national security commission said lawmakers would consider the possibility of enriching uranium to weapons-grade levels if conflict resumed.
"One of Iran's options in the event of another attack could be 90 percent enrichment. We will examine it in parliament," Ebrahim Rezaei wrote in a post on X.
Tehran possesses a significant stockpile of uranium enriched to 60 percent purity, with roughly 90 percent required for a nuclear weapon.
Iran's stockpile of highly enriched uranium remains a key sticking point in negotiations with the United States, which insists the material must be transferred out of the country.
Iran has so far refused to move its enriched uranium stockpile abroad and insists on its right to the peaceful use of nuclear energy, though it has said the level of enrichment remains "negotiable".
