The US and Iran failed to reach an agreement to end their war despite ​marathon talks that concluded on Sunday in the Pakistani capital, Islamabad, jeopardising a fragile ceasefire.

Each side blamed the other for the failure of the 21-hour negotiations to end fighting that ‌has killed thousands and sent global oil prices soaring since it began over six weeks ago.

“The bad news is that we have not reached an agreement, and I think that’s bad news for Iran much more than it’s bad news for the United States of America,” Vice President JD Vance, the head of the US delegation, told reporters shortly before he left Islamabad.

US Cities ‘Red Lines’, Iran Says Demands ‘Excessive’

“So we go back to the United States, having not come to an agreement. We’ve made very clear ​what our red lines are.”

The US and Iranian delegations have left Islamabad to return home, Pakistani sources told Reuters.

Vance said Iran had chosen not to accept American terms, including not to build nuclear ​weapons.

“We need to see an affirmative commitment that they will not seek a nuclear weapon, and they will not seek the tools that would enable them to quickly achieve a nuclear weapon. That is the core goal of the president of the United States, and that's what we've tried to achieve through these negotiations.”

The talks in Islamabad, after a ceasefire earlier in ​the week, were the first direct US-Iranian meeting in more than a decade and the highest-level discussions since the 1979 Islamic Revolution.

Iran’s semi-official Tasnim news agency said that “excessive” US demands had hindered reaching an agreement. Other Iranian ​media said there was agreement on a number of issues but that the Strait of Hormuz and Iran’s nuclear programme were the main points of difference.

A spokesperson for Iran’s foreign ministry said the talks were conducted in an atmosphere of mistrust. “It is natural that we shouldn’t have expected to reach agreement in just one session,” the spokesperson was quoted as saying by Iranian media.

Pakistan’s Foreign Minister Ishaq Dar said it was “imperative” to maintain the two-week ceasefire that was agreed on Tuesday as the ​two sides attempted to wind down a war that began on February 28 with air strikes by the US and Israel on Iran.

Israeli security cabinet minister Zeev Elkin told Army Radio that more talks were ​still an option, but warned: “The Iranians are playing with fire.”

In his brief press conference, Vance did not mention reopening the Strait of Hormuz, a choke point for about 20 percent of global energy supplies that Tehran has blocked since the war ‌began.

Vance said ⁠he had spoken with President Donald Trump as many as a dozen times during the talks. But even as the negotiations continued, Trump said on Saturday that a deal was not entirely necessary.

“We’re negotiating. Whether we make a deal or not makes no difference to me, because we’ve won,” he told reporters.

The US delegation included special envoy Steve Witkoff and Trump’s son-in-law, Jared Kushner. Iran’s team included Parliamentary Speaker Mohammad Baqer Qalibaf and Foreign Minister Abbas Araqchi.

Strait of Hormuz

“There were mood swings from the two sides and the temperature went up and down during the meeting,” a Pakistani source said in reference to an early round of talks, which began on Saturday ​and carried on overnight.

Before the talks began, a senior ​Iranian source told Reuters the US had agreed ⁠to release frozen assets in Qatar and other foreign banks. A US official denied agreeing to release the money.

As well as the release of assets abroad, Tehran is demanding control of the Strait of Hormuz, payment of war reparations and a ceasefire across the region, including in Lebanon, according to Iranian state TV and officials.

Tehran ​also wants to collect transit fees in the Strait of Hormuz.

Despite the differences in Islamabad, three supertankers fully laden with oil passed through the Strait of Hormuz on ​Saturday, shipping data showed, in what appeared to be the first vessels to exit the Gulf since the ceasefire deal.

Hundreds of tankers are still stuck in the Gulf, waiting to exit during the two-week ceasefire period.

Trump’s stated goals have shifted, but as a minimum, he wants free passage for global shipping through the strait and the crippling of Iran’s nuclear enrichment programme to ensure it cannot produce an atomic bomb.

Tehran has long denied seeking to build a nuclear weapon.

US ally Israel has also been bombing ​Tehran-backed Hezbollah militants in Lebanon and says that the conflict is not part of the Iran-US ceasefire. Iran has insisted that the fighting ​in Lebanon has to stop.

The Israeli military said it struck Hezbollah rocket launchers overnight between Saturday and Sunday, and black smoke could be seen rising in the southern suburbs of the Lebanese capital, Beirut, on Sunday. In Israeli villages near the border, air raid ​sirens sounded, warning of incoming rocket fire from Lebanon.