Iran's foreign ministry said Monday it had called for an end to the war across the region and the release of frozen assets abroad in its response to the latest U.S. proposal.

"We did not demand any concessions. The only thing we demanded was Iran's legitimate rights," said ministry spokesman Esmaeil Baqaei in a weekly press briefing.

U.S. President Donald Trump on Sunday accused Iran of "playing games" and laughing at America for decades, but said it soon would be made to stop -- without commenting directly on reports of Tehran's response to Washington's latest peace proposal.

Iran's Islamic Revolutionary Guards threatened Saturday to target U.S. sites in the Middle East if its tankers come under fire, Iranian media reported, as Washington was left waiting for Tehran's response to its latest negotiating position.

Iran's army warned on Sunday that countries complying with U.S. sanctions against the Islamic republic would face difficulties crossing the Strait of Hormuz.

An unknown projectile struck a ship off the coast of Qatar early Sunday morning, a UK maritime agency reported, after Iran's Islamic Revolutionary Guards threatened to target U.S. vessels in the region.

U.S. President Donald Trump said Friday that he was expecting Iran's response to Washington's latest proposal on a deal to ending the Middle East war by "tonight."

A U.S. fighter jet disabled two Iranian-flagged tankers to enforce a port blockade on Friday, prompting retaliatory attacks and rattling a shaky truce as Tehran weighed Washington's latest proposal to end the Middle East war.

U.S. Secretary of State Marco Rubio on Friday slammed Iranian efforts to control the Strait of Hormuz, following a report that Tehran has created an authority to approve transit through the vital waterway.

"Iran now claims that they own, that they have a right to control, an international waterway... That's an unacceptable thing that they're trying to normalise," Rubio told reporters during a visit to Rome.

The United Arab Emirates said it responded to another Iranian missile barrage on Friday, hours after the U.S. said it traded fire with Iranian forces in the Strait of Hormuz, in the latest blows to a shaky month-old ceasefire.

The UAE’s Defense Ministry said three people were wounded after air defenses engaged two ballistic missiles and three drones launched by Iran. It was not clear if all were successfully intercepted. Authorities told people to stay away from any fallen debris.

The U.S. military said it carried out strikes on Iranian military targets in response, although Tehran charged that it was Washington that had initiated the exchange of fire.

The latest violence threatens to unravel a fragile truce in effect since April 8 that brought an end to weeks of U.S.-Israeli attacks on the Islamic republic, which has retaliated with strikes across the Middle East and by blocking the strait, a vital route for oil and gas shipments.