Iran live updates: Gulf countries under attack after US completes 3rd round of retaliatory strikes

U.S. negotiators are not present in Oman for talks with Iran, a U.S. official told ABC News Saturday.

"US technical teams will not be present in Oman but will be in touch with the Omanis and Qataris as developments occur," the official said.

On Friday, a senior U.S. official had said that negotiations would resume in Oman, but did not say if U.S. teams would be physically present. Another U.S. official said they expected Iran to publicly say they’ll stop attacking ships in the Strait of Hormuz after those talks, but according to the statement from Iran’s official news agency IRNA, no such commitment was made.

Iran’s official news agency IRNA said Omani and Iranian officials discussed “mechanisms for the safe passage of ships” and stressed Oman’s position on “the use of diplomacy to prevent the escalation of tension in the region.”

-ABC News' Selina Wang

Iran's Supreme Leader Ayatollah Mojtaba Khamenei said on Saturday that avenging his slain predecessor and father was "the demand of the nation" and "must certainly" take place, according to a message released by state television.

Khamenei issued the message on the occasion of funeral ceremonies for his father, Ayatollah Ali Khamenei, held months after he was killed in the U.S.-Israeli airstrikes on February 28.

"We pledge to avenge the blood of the martyred leader and all the martyrs of these two wars from the criminal and disgraced killers," Khamenei said in the message.

-ABC News' Rashid Haddou

President Donald Trump said "1000 Missiles are Locked and Loaded and aimed at Iran," should the government attempt to assassinate him.

In a post on his social media platform, Trump said the U.S. military is "ready, willing, and able, for a one year period of time, subject to extension, to completely decimate and destroy all areas of Iran."

A U.S. official said that the question of nuclear dust "still very much is on the table" -- using a phrase to describe Iran's highly enriched uranium that remains covered in rubble after U.S. airstrikes.

"Either they're going to give us the nuclear dust or we have very low-cost military options to ensure that it remains buried underground forever," one U.S. official said.

The U.S. official later added that the nuclear materials are key to the deal.

"We have a lot of options if they resist giving the dust. There are continued military, diplomatic, economic leverage points. That's my point there, is that the United States fundamentally has the cards. We want the dust," the U.S. official said.

"But I want to be clear here that if we don't get the dust, we do not have a deal with Iran," the U.S. official said.

-ABC News' Michelle Stoddart