President Donald Trump and senior U.S. defense officials laid out an open-ended timeline for the ongoing operation against Iran on Monday, announcing more U.S. forces are headed to the region to carry out the American and Israeli campaign aimed at dismantling Tehran’s long-range strike capabilities and nuclear ambitions.

Speaking to reporters at the White House on Monday morning, Trump said that U.S. forces were “already substantially ahead of our time projections” with their mission in Iran, but added that the American military was prepared to continue the operation beyond his initial four-to-five week timeline. 

“Whatever the time is, it’s OK. Whatever it takes,” Trump said at a Medal of Honor ceremony. “Right from the beginning, we projected four to five weeks, but we have capability to go far longer than that. We’ll do it.”

The president told CNN Monday morning that the “big wave hasn’t even happened. The big one is coming soon.” 

Adm. Brad Cooper, head of CENTCOM, “will receive additional forces even today,” said Gen. Dan Caine, chairman of the Joint Chiefs of Staff, during a separate press briefing alongside Defense Secretary Pete Hegseth. “This rapid buildup of forces demonstrated the joint forces ability to adapt and project power at the time and place of our nation’s choosing.”

Caine also made clear the weekend barrage was only the beginning. 

“This is not a single overnight operation,” he said. Caine noted that the operation was the result of “months, and in some cases years,” of planning. “The military objectives that CENTCOM and the Joint Force have been tasked with will take some time to achieve, and in some cases, will be difficult and gritty work. We expect to take additional losses.” Four U.S. servicemembers have already been killed in the course of the operations.

While officials emphasized that there are currently no American boots on the ground in Iran, Hegseth declined to rule out the possibility, saying the United States “will go as far as we need to go to advance American interests.” 

Trump similarly kept the door open to a ground invasion in an interview with the New York Post. “Every president says, ‘There will be no boots on the ground.’ I don’t say it,” Trump said. “I say ‘probably don’t need them,’ [or] ‘if they were necessary.’”

Hegseth likewise acknowledged that a military effort “of this scope will include casualties” and declined to provide a timeline for completion. “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,” Hegseth said.

“The commander in chief sets the tempo in terms of this fight. As I said, it’s on his terms,” said Hegseth. “Why in the world would we tell the enemy exactly how long we’ll go or how far we’ll go?” 

“To the media outlets and political left screaming ‘endless wars’ — stop,” Hegseth added. “This is not Iraq. This is not endless.” He argued that the operation is “clear, devastating, decisive” with narrowly defined objectives: “destroy the missile threat, destroy the Navy, no nukes.”

Trump also laid out his four priorities for the campaign: “First, we’re destroying Iran’s missile capabilities … Second, we’re annihilating their navy … 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,” he said.

Hegseth insisted the campaign is not designed to topple Iran’s government, stressing that “this is not a war of regime change.” However, he noted that “the regime sure did change, and the world is better off for it today.” 

Iranian leadership “had every chance to make a peaceful and sensible deal, but Tehran was not negotiating,” said Hegseth. “They were stalling, buying time to reload their missile stockpiles and restart their nuclear ambitions.”

Hegseth framed the military confrontation as the culmination of decades of Iranian aggression against the United States, arguing that Tehran’s missile and proxy network had created a conventional shield for its nuclear ambitions and left American forces and allies in its crosshairs.

“For 47 long years, the expansionist and Islamist regime in Tehran has waged a savage, one-sided war against America,” said Hegseth, calling the moment a “generational turning point.” 

“We didn’t start this war, but under President Trump, we are finishing it,” Hegseth said.

Speaking about cooperation with partners, Hegseth noted that Israel “did a great job in the conduct of that operation,” also stating that the U.S.’ integrated air and missile defense network has intercepted “hundreds of ballistic missiles targeting U.S. forces, our partners and regional stability.” 

“As the threat grew, our partners surged in beside us,” said Hegseth. “Air defense batteries in Qatar, the UAE, Kuwait, Jordan and Saudi Arabia joined the fight. Proof that years of training, trust and hard-earned integration pay off.”