PALM BEACH, United States, March 2, 2026 (BSS/AFP) - President Donald Trump on Sunday sought to justify the military operation against Iran by citing the need to ensure America's long-term security, and to prepare the public for further casualties after the deaths of three US troops.

"Sadly, there will likely be more before it ends," Trump said in a video address published on his Truth Social platform, responding to news of the casualties.

"America will avenge their deaths and deliver the most punishing blow to the terrorists who have waged war against, basically, civilization," the US president said from his Mar-a-Lago residence in Florida.

Trump has not addressed the nation directly since the start of the war against Iran on Saturday, but he has released two video messages, announced the death of Iranian supreme leader Ali Khamenei on Truth Social, and had several telephone interviews with journalists.

Trump did not speak to reporters on Air Force One as he returned to Washington from Florida.

Senior officials from his administration are due to make the case for the attack on Iran before the US Congress on Tuesday, the White House said.

- 'Four weeks' -

"It's always been a four-week process. We figured it will be four weeks or so," Trump told British newspaper the Daily Mail about the length of the war.

He was meanwhile quoted as saying in an interview with Fox News: "Nobody can believe the success we're having, 48 leaders are gone in one shot. And it's moving along rapidly."

Trump told NBC News that "we expect casualties, but in the end it's going to be a great deal for the world," after the US military announced three service members had been killed.

Trump said: "We're undertaking this massive operation not merely to ensure security for our own time and place, but for our children and their children."

"These actions are right and they are necessary to ensure that Americans will never have to face a radical, bloodthirsty terrorist regime armed with nuclear weapons and lots of threats," he said.

- Ships sunk -

"I have just been informed that we have destroyed and sunk 9 Iranian Naval Ships, some of them relatively large and important," Trump said on his Truth Social network.

"We are going after the rest -- They will soon be floating at the bottom of the sea, also! In a different attack, we largely destroyed their Naval Headquarters," he said.

Neither Trump nor other top US officials such as Secretary of State Marco Rubio and Pentagon chief Pete Hegseth have appeared in public since the start of the war.

The Atlantic magazine quoted Trump as saying that Iran's leaders "want to talk, and I have agreed to talk, so I will be talking to them. They should have done it sooner."

But "most of those people are gone," he said.

Trump told CNBC in an interview that "we're doing our job not just for us but for the world. And everything is ahead of schedule."

"Things are evolving in a very positive way right now, a very positive way," he said.