RIYADH, Saudi Arabia — Iran’s foreign minister said yesterday that Britain must say its 15 sailors and marines entered Iranian waters in order to resolve a standoff over their capture by Iran.

Manouchehr Mottaki’s statement in an interview with the Associated Press came on a day of escalating tensions, highlighted by an Iranian video of the detained Britons that showed the only woman captive saying her group had “trespassed” in Iranian waters. Britain angrily denounced the video as unacceptable and froze most dealings with Iran.

Mr. Mottaki said that if the alleged entry into Iranian waters was a mistake, “this can be solved. But they have to show that it was a mistake, that will help us to end this issue.”

“Admitting the mistake will facilitate a solution to the problem,” he said late last night in Riyadh, Saudi Arabia, where he was attending a summit of Arab leaders.

It was the first time that Iran has publicly suggested a way to resolve the crisis, but British acquiescence appeared unlikely as the country has been insisting since the crisis began that its troops were in Iraqi waters and released documents yesterday to back up the claim.

There was no immediate comment from the British to Mr. Mottaki’s statement. A call to Britain’s Foreign Office in London was not answered early today. Mr. Mottaki also backed off a prediction that the female sailor, Faye Turney, could be freed yesterday or today, but he said Tehran agreed to allow British officials to meet with service personnel.

“We have accepted that [the British request], there is no problem. Measures are underway [to arrange meeting.] They can meet them,” he said.

Prime Minister Blair’s government announced it was freezing all dealings with Iran except to negotiate the release of its personnel, adding to a public exchange of sharp comments that helped fuel a spike in world oil prices.