ERBIL, Kurdistan Region of Iraq – Negotiations between the US and Iran in Islamabad have not produced an agreement, US Vice President JD Vance said Sunday, after over 20 hours of Pakistan-mediated negotiations aimed at ensuring a lasting ceasefire and ending the war.

High-level US and Iranian delegations arrived in Islamabad on Saturday, with the two sides holding extensive talks for 21 hours aimed at ending the war.

“We’ve had a number of substantive discussions with the Iranians. That’s the good news. 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,” Vance said.

Iranian foreign ministry spokesperson Esmail Baghaei said Saturday that the Strait of Hormuz, the nuclear program, war reparations, lifting of sanctions, and a “complete end” to the war were discussed.

Iran has closed the Strait of Hormuz, a key waterway responsible for roughly 20 percent of the world’s oil, as a means in its war against the US and Israel, sharply driving up oil prices.

“The success of this diplomatic process depends on the seriousness and good faith of the opposing side, refraining from excessive demands and unlawful requests, and the acceptance of Iran's legitimate rights and interests,” Baghaei said in a statement.

Media affiliated with Iran’s Islamic Revolutionary Guard Corps (IRGC) cited “excessive demands” made by the US delegation as a reason for the talks failing. 

Before leaving Islamabad, Vance said that Washington had given Tehran its “final and best offer.” 

After the talks ended, Pakistani Foreign Minister Ishaq Dar said it will continue mediating between Washington and Tehran in the coming days, adding, “It is imperative that the parties continue to uphold their commitment to the ceasefire.”

“We hope that the two sides continue with the positive spirit to achieve durable peace and prosperity for the entire region and beyond,” Dar said.

A two-week ceasefire between the US and Iran reached on April 7 has led to a lull in attacks in the region, with the Iran-aligned Islamic Resistance in Iraq, an umbrella group of Shiite militias, on Wednesday saying that it too will refrain from offensive action during the period.

Since the US-Israel war with Iran started in late February, many top Iranian leaders and officials have been killed, including the late Supreme Leader Ayatollah Ali Khamenei, Secretary of Iran’s Supreme National Security Council (SNSC) Ali Larijani, and the commander of the Basij unit of the IRGC Gholamreza Soleimani.

There are also unconfirmed reports that the newly appointed Supreme Leader Mojtaba Khamenei has suffered injuries in an airstrike.