Operation Epic Fury will continue without a public time frame, as War Secretary Pete Hegseth said Monday the U.S. mission in Iran is not a "regime-change war," while the Pentagon warned more American casualties are expected.
Hegseth said the United States "didn’t start this war, but we’ll finish it," accusing the Iranian regime of waging war against the U.S. "for 47 long years" through proxy attacks.
"They did it through the blood of our people. Car bombs in Beirut, rocket attacks on our ships, murders at our embassies, roadside bombs in Iraq and Afghanistan funded and armed by Iranian Quds Force and IRGC killers," Hegseth stated at the Pentagon.
He described 'Operation Epic Fury' as "the most lethal, most complex and most precise aerial operation in history," saying Iran "was building powerful missiles and drones to create a conventional shield for their nuclear blackmail ambitions."
"Iran had a conventional gun to our head as they tried to lie their way to a nuclear bomb," he stated.
Hegseth declined to estimate how long Operation Epic Fury would last.
"As far as time frame, I would never hang a time frame," Hegseth said, adding that U.S. President Donald Trump "has all the latitude in the world" to describe whether it may take "four weeks, two weeks, six weeks," and that timelines "could move up" or "move back."
He said the U.S. would "execute what we need on our own timeline" and carry out objectives "at his command."
Hegseth said Iran has long-range strike capabilities "which we are hyper focused on."
Hegseth said the mission is "laser-focused" on destroying Iranian offensive missiles, missile production, the navy and other security infrastructure to ensure "they will never have nuclear weapons."
"This is not Iraq. This is not endless," he said, rejecting comparisons to past U.S. wars in Iraq and Afghanistan.
"To the media outlets and political left screaming endless wars, stop," Hegseth stated.
"He called the last 20 years of nation-building wars dumb. And he’s right. This is the opposite," he noted.
He said the campaign involves "no stupid rules of engagement, no nation-building quagmire, no democracy building exercise, no politically correct wars."
"We fight to win and we don’t waste time or lives," he said, adding, "War is hell."
Hegseth also said, "This is not a so-called regime change war, but the regime sure did change and the world is better off for it."
Referring to the deaths of Iranian leaders, he said, "Turns out the regime who chanted 'Death to America' and 'Death to Israel' was gifted death from America and death from Israel."
His remarks followed U.S. and Israeli strikes launched Feb. 28 that killed Iran's Supreme Leader Ali Khamenei and other top security officials.
Gen. Dan Caine, chairman of the Joint Chiefs of Staff, provided a detailed timeline of Operation Epic Fury.
"At 15:38, 3:38pm, on Friday, February 27, the United States Central Command, through the Secretary of War, received the final go from President Trump," Caine said.
"The president directed, and I quote, ‘Operation Epic Fury is approved. No aborts. Good luck. Close.’," he added.
That timeline places Trump aboard Air Force One en route to Texas. He landed in Corpus Christi at 3:50 p.m. ET.
Later that day in Corpus Christi, where he was promoting his energy agenda, Trump said: "We have a big decision to make." He called it "not easy" and said Iran had long engaged in malign behavior.
Caine said U.S. Cyber Command and U.S. Space Command acted first, layering "nonkinetic effects" that disrupted, degraded and blinded Iran's "ability to see, communicate and respond at the H-hour."
The full operation began at 1:15 a.m. Eastern on Saturday when "the skies surged to life," Caine said. He described it as "a daylight strike based on a trigger event conducted by the Israeli army, enabled by the U.S. intelligence community."
"More than 1,000 targets were hit in the first 24 hours," he stated.
Caine said the strikes resulted in "local air superiority" across Iran, enhancing force protection and enabling continued operations.
Four U.S. service members have been killed in the conflict, U.S. Central Command said Monday. The latest died after being "seriously wounded during Iran’s initial attacks," according to an X post.
Caine offered "deepest and heartfelt condolences" to their families, calling the fallen "heroes."
"This is not a single overnight operation," Caine stated, adding that, "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 and as always, we will work to minimize U.S. losses," he said.
Hegseth echoed that warning, saying, "An effort of this scope will include casualties. War is hell."
Caine said "operations will remain active across the theater and across the globe," and that U.S. forces are postured "to maintain pressure, but to respond and adapt as required."
He warned those who "would test our resolve or threaten the United States, our allies or interests" that "we can reach you, we can sustain the fight, and we can scale the fight, and we will prevail."
Hegseth also stated that there are currently no U.S. "boots on the ground" in Iran but refused to rule out future steps.
"We’re not going to go into the exercise of what we will or will not do," he stated, calling it "foolishness" to publicly outline military plans.
He said the United States would "go as far as we need to go to advance American interests," but added, "We're not dumb about it. You don’t have to roll 200,000 people in there and stay for 20 years."
As the briefing ended, Hegseth again declined to provide a time frame for Operation Epic Fury, saying the president would determine the length of the campaign and look for "opportunities, off ramps" or moments to escalate.
Operation Epic Fury, he stated that, is designed to destroy Iranian military threats and nuclear capabilities and "is not endless."