President Trump said the U.S.-Israeli war on Iran represented the "last best chance" of addressing the threat posed by the Islamic Republic's ballistic missiles and nuclear program.
He also said the administration expects the campaign to last four to five weeks, but "we have [the] capability to go far longer than that."
Speaking at a Medal of Honor ceremony at the White House, the president said Iran ignored the United States' warnings to cease their pursuit of nuclear weapons. He said the regime's "rapidly" growing conventional ballistic missile program posed a "very clear, colossal threat" to the U.S. and forces stationed overseas.
"This was our last best chance to strike, what we're doing right now, and eliminate the intolerable threats posed by this sick and sinister regime," the president told his audience. "And they are indeed sick and sinister."
The president said the Iranian leadership "already had missiles capable of hitting Europe and our bases both local and overseas, and would soon have had missiles capable of reaching our beautiful America." The objectives for the mission, he said, "are clear," listing four of them.
"First, we're destroying Iran's missile capabilities, and you see that happening on an hourly basis, and their capacity to produce brand-new ones," he said. "Second, we're annihilating their Navy. We've knocked out already 10 ships. They're at the bottom of the sea. Third, we're ensuring that the world's number one sponsor of terror can never obtain a nuclear weapon. … And finally, we're ensuring that the Iranian regime cannot continue to arm, fund and direct terrorist armies outside of their borders."
In an interview earlier in the day, he refused to rule out the use of ground troops, saying he wouldn't hesitate to deploy them "if they were necessary."
"I don't have the yips with respect to boots on the ground — like every president says, 'There will be no boots on the ground.' I don't say it," the president told The New York Post. "I say 'probably don't need them,' [or] 'if they were necessary.'"
In a briefing Monday morning, Defense Secretary Pete Hegseth likewise declined to rule out the use of ground troops. He said there are not currently any U.S. service members on the ground in Iran, but added, "We're not going to go into the exercise of what we will or will not do."
Mr. Trump said the U.S. military will "easily prevail" over the Iranian regime. He hinted that the timeline for the war drag on longer than the initial four or five weeks he mentioned previously.
"We're already substantially ahead of our time projections, but whatever the time is, it's OK. Whatever it takes, we will always, and we have right from the beginning, we projected four to five weeks. But we have capability to go far longer than that. We'll do whatever," he said. "Somebody said today, they said, 'Oh well, the president wants to do it really quickly. After that, he'll get bored.' I don't get bored. There's nothing boring about this."
Mr. Trump spoke at the White House after his interview with the Post, his first public event since the beginning of the U.S.-Israeli war with Iran over the weekend. He had released pre-recorded videos but had not addressed the bombing campaign in person.
"Today, the United States military continues to carry out large-scale combat operations in Iran to eliminate the grave threats posed to America by this terrible terrorist regime," he said at the beginning of a Medal of Honor ceremony.
The president was at Mar-a-Lago in Florida during the initial phase of the war, monitoring developments from his estate, and returned to the White House on Sunday evening.
Four U.S. service members have been killed in Operation Epic Fury so far, according to the U.S. military. Hegseth said that the troops were killed by a munition that hit a tactical operations center in Kuwait.
"Today, we grieve for the four heroic American service members who have been killed in action, and send our love and support to their families," the president said Monday. "In their memory, we continue this mission with ferocious, unyielding resolve to crush the threat this terrorist regime poses to the American people, and a threat indeed it is."
In a video message Sunday night, Mr. Trump said he expects there to be more American casualties, but combat operations "will continue until all of our objectives are achieved."
"We pray for the full recovery of the wounded and send our immense love and eternal gratitude to the families of the fallen," he said. "And sadly, there will likely be more before it ends. That's the way it is."
Israeli strikes at the beginning of the conflict killed Supreme Leader Ayatollah Ali Khamenei, along with dozens of other top officials. More than 1,000 targets were hit over the first 24 hours of the ensuing bombing campaign, according to Gen. Dan Caine, the chairman of the Joint Chiefs of Staff. Iran has retaliated with barrages of missile and drone attacks on Israel, Gulf nations and U.S. facilities in the region.
Mr. Trump first said Sunday that he expects the U.S. assaults to continue for four or five weeks. Hegseth was asked about that timeline, and dismissed it as a "gotcha-type question."
"President Trump has all the latitude in the world to talk about how long it may or may not take — four weeks, two weeks, six weeks. It could move up. It could move back," he said. "We're going to execute at his command the objectives we've set out to achieve."
