Iran live updates: 7th killed service member is identified

Iranian state media shared a photo of a meeting of the interim leadership council on Sunday.

The picture shows Iranian President Masoud Pezeshkian, Chief Justice Gholam Hossein Mohseni Ejehi and a Secretary of the Guardian Council, Alireza Arafi, sitting around a table in a room. The Islamic Republic of Iran Broadcasting said this is the second meeting of the interim leadership council.

Based on the Islamic Republic's constitution, the council temporarily takes over the leader's responsibilities until a new leader is chosen by the Assembly of the Experts.

-ABC News' Somayeh Malekian

As President Donald Trump departed for Mar-a-Lago on Sunday, he posted a video on social media acknowledging for the first time on camera the death of three U.S. troops killed during the U.S. operation against Iran over the weekend.

The president said he was sending "our immense love and eternal gratitude to the families of the fallen" before warning that more U.S. troops will "likely" be killed as the operation rages on.

"Earlier today, CENTCOM shared the news that three U.S. military service members have been killed in action. As one nation, we grieve for the true American patriots who have made the ultimate sacrifice for our nation, even as we continue the righteous mission for which they gave their lives, we pray for the full recovery of the wounded and send our immense love and eternal gratitude to the families of the fallen," Trump said.

"And sadly, there will likely be more before it ends. That's the way it is -- likely be more, but we'll do everything possible. But that won't be the case. But America will avenge their deaths and deliver the most punishing blow to the terrorists who have waged war against, basically, civilization," Trump added.

Trump started the speech by touting the nine Iranian naval vessels he said were sunk, and said, for the first time on camera, that the Ayatollah was dead. The president also said that "the entire military command is gone" in Iran.

Later in the speech, Trump warned that those who did not surrender would face "certain death."

-ABC News' Meghan Mistry, Nicholas Kerr, Fritz Farrow and Selina Wang

U.S. lawmakers in the House and Senate will receive classified briefings on Tuesday from Trump administration officials on the military operation in Iran, multiple sources told ABC News.

Senators are scheduled to be briefed at 3:30 p.m. ET on Tuesday. A briefing for House members will follow at around 5 p.m., according to the sources

The briefers from the administration are expected to include Secretary of State Marco Rubio, Joint Chiefs Chairman Gen. Dan Caine, CIA Director John Ratcliffe, and Secretary of Defense Pete Hegseth, according to the sources.

-ABC News' Jay O'Brien and Lauren Peller

Iran's foreign minister, Abbas Araghchi, told his Omani counterpart on Sunday that Tehran welcomes "any serious efforts contributing to de-escalation and the restoration of stability," according to a social media post from the Oman News Agency.

The post said Omani Foreign Minister Badr bin Hamad Al Busaidii, who had been mediating the negotiations between the United States and Iran leading up to Saturday's joint U.S.-Israel military operation, spoke with Araghchi by phone.

Araghchi "conveyed the position of the Islamic Republic of Iran, which calls for peace, noting that the Israeli-US attack upon his country had exacerbated tension and alarm throughout the region, while affirming the Iranian side's openness to any serious efforts contributing to de-escalation and the restoration of stability," the post read.

The post further said al-Busaidii "affirms the Sultanate of Oman's continued advocacy for a ceasefire and a return to dialogue and negotiation to resolve the ongoing conflict through diplomatic means."

-ABC News' Somayeh Malekian