Iran and the United States failed to strike a deal Sunday to end the war in the Middle East, but there was no immediate return to hostilities and world leaders quickly urged both sides to pursue the diplomatic route to peace.

U.S. President Donald Trump on Sunday ordered a U.S. naval blockade of the Strait of Hormuz in response to Iran's "unyielding" refusal to give up its nuclear ambitions during peace talks in Islamabad.

While acknowledging that the marathon negotiations in Pakistan had gone "well" and "most points were agreed to," Trump said Tehran had refused to concede on the issue of its nuclear program.

Pakistan's foreign minister insisted on Sunday Washington and Tehran must uphold a ceasefire agreement, after marathon talks between the two sides to end the war in the Middle East ended without an agreement.

Iran's foreign ministry said no one had held any expectation that talks with the United States could have reached an agreement within one session after the negotiations in Islamabad stalled on Sunday.

Iran and the United States failed to reach an agreement to end the war in the Middle East, U.S. Vice President JD Vance said Sunday after marathon talks in Islamabad, adding that he was leaving after giving Tehran the "final and best offer".

Israeli Prime Minister Benjamin Netanyahu said on Saturday that the joint U.S.-Israeli campaign against Iran had succeeded in "crushing" the Islamic republic's nuclear and ballistic missile programs.

Two U.S. Navy warships transited the Strait of Hormuz to begin clearing Iranian-laid mines, U.S. Central Command said Saturday -- a claim Tehran denied as the Revolutionary Guards threatened to deal "severely" with military vessels crossing the strategic waterway.

U.S. President Donald Trump said prior to the failure of the Islamabad talks that he was not bothered about any outcome of the negotiations, insisting the United States had come out ahead from the war.

American and Iranian officials were holding face-to-face talks in Pakistan on Saturday, the most significant since the 1979 Islamic revolution as the foes try to end a war that plunged the Middle East into violence and rocked the world economy.

U.S. President Donald Trump vowed Friday to have the Strait of Hormuz open "with or without" Iran's cooperation, and said his top priority in peace talks was to ensure Tehran can't have a nuclear weapon.