Defense Secretary Pete Hegseth said Thursday the U.S. can “sustain the fight for as long as it takes” as the war against Iran continues for a sixth day, with a top military official indicating the U.S.’s focus will shift to razing Iran’s missile industry.

Hegseth gave a press briefing in Tampa with Admiral Brad Cooper, the commander of U.S. Central Command leading U.S. forces in the Middle East. Thursday’s briefing came one day after Hegseth said the mission, named Operation Epic Fury, against Iran was “just getting started.” Hegseth also announced Wednesday that an Iranian warship had been sunk by a U.S. torpedo, the first time the U.S. Navy has sunk a warship with a torpedo since World War II. 

Hegseth told reporters Thursday: “Our timeline is ours and ours alone to control.”

He also said the U.S. has “no shortage of munitions.” CBS News reported earlier Thursday that Arab states in the Persian Gulf region are running dangerously low on interceptors to take down Iranian retaliatory attacks. 

Cooper said the next phase of the operation will focus in part on trying to “systemically dismantle Iran’s missile production capability for the future.” He said that mission — which is seeking to “raze or level” Iran’s missile industry— is currently underway but will “take some time.”

“We’re not just hitting what they have. We’re destroying their ability to rebuild,” he said.

He said in the last 72 hours, America’s bomber force has struck nearly 200 targets deep inside of Iran, including around Tehran, and on Thursday, B-2 bombers dropped “dozens of 2,000-pound penetrators” targeting deeply buried ballistic missile launchers. According to Cooper, Iranian ballistic missile and drone attacks have decreased significantly as the war has progressed.

U.S. forces have now destroyed 30 Iranian vessels, according to Cooper, including a drone carrier that is roughly the size of a World War II aircraft carrier. 

Hegseth told reporters the U.S. is also “establishing total dominance over the skies.”

H.R. McMaster, a CBS News contributor who served as national security advisor in President Trump’s first term, said after the press conference that U.S. strikes on air defenses “you can fly all kinds of aircraft with complete impunity.”

Six U.S. Army Reserve members have been killed in the war with Iran. Hegseth had said the deadly incident happened when an incoming munition hit a tactical operations center in Kuwait.

Hegseth said Thursday the U.S. military will “remember and honor” the six people who were killed by “rededicating ourselves even more fervently to this mission.”

Hegseth is participating in the press conference during a visit to U.S. Central Command headquarters in Tampa. This is the first time Cooper is giving a press briefing since the campaign began over the weekend. 

On Monday night, he released a social media video expressing his condolences for the six service members killed over the weekend and gave an operational update on the campaign. 

He said the U.S. had struck nearly 2,000 targets with over 2,000 munitions. He said more than 50,000 troops, 200 fighter aircraft, two carrier strike groups, and bombers from the U.S. are participating, “representing the largest buildup by the U.S. in the Middle East in a generation.”