In a video posted on X, Admiral Brad Cooper, head of Central Command, also estimated that 92 percent of the Iranian navy's largest vessels had been damaged or destroyed.

"And my operational assessment is that they've now lost the ability to meaningfully project naval power and influence around the region and around the world."

With the war now in its fourth week, he added that "we remain on plan or ahead of plan in achieving very clear objectives" for the war launched with Israel.

"We have damaged or destroyed over two-thirds of Iran's missile drone and naval production facilities and shipyards, and we're not done yet," he said, adding that US forces had now struck over 10,000 military targets.

Iran has retaliated for the US and Israeli strikes by launching missiles at targets throughout the Gulf almost daily.

But Cooper said that Iran's drone and missile launch rates were down by 90 percent, and "we've also removed the regime's ability to rebuild them."

Iranian Foreign Minister Abbas Araghchi said Wednesday that Iran did not plan to negotiate with the United States and intended to keep fighting, after the White House said talks were ongoing.