Between Iranian offiicals and security men, British navy personnel make their way to meet with Iranian President Mahmoud Ahmadinejad in Teran. AP Photo/Mehr News Agency, Sajjad Safari   Iranian president Mahmoud Ahmadinejad speaks to the media at a press conference in Tehran. He has released 15 detained British navy personnel. AP Photo/Vahid Salemi

Iranian President Mahmoud Ahmadinejad issued the surprise news in a Tehran news conference. It was still unclear at midday when the captives — President Bush and others have called them "hostages" — would arrive at the British Embassy in Tehran.

Bush administration officials reacted positively, but hesitantly, aware that the crisis was not yet entirely over and allowing British Prime Minister Tony Blair to do the lion's share of the public talking.

"I note that Prime Minister Blair has welcomed this," Gordon Johndroe, the White House's national security spokesman, said from aboard Air Force One as Bush traveled to California. "We share his sentiments but this is very recent information so we need to see how it develops."

Said Cheney: "I don't know all the details, obviously, but I'm glad to know that the British sailors are apparently going to be released." Iran has disputed the U.S. characterization of the sailors as hostages.

"There's considerable evidence that they were, in fact, in Iraqi territorial waters when this happened," Cheney said in an interview today with ABC News, referring to Britain's denial of Iranian claims that the crew had entered Iranian waters and thus were legitimately taken.

"And so it's one of those events that should not have happened," he added. "I think the Iranians were wrong to capture the sailors and it's good now that they have been released."

Ahmadinejad's announcement came after Iran's state media reported that an Iranian envoy would be allowed to meet five Iranians detained by U.S. forces in northern Iraq. Another Iranian diplomat, separately seized two months ago by uniformed gunmen in Iraq, was released and returned Tuesday to Tehran.

Cheney said "I don't know" if those developments or others meant there had been any quid pro quo to secure the captives' release.

"I don't think there should have been," he said, echoing Bush's repeated statements. "It's important that if you get into the business where you reward that kind of behavior, there'll be more of that kind of behavior."

Johndroe said it was unlikely there was any connection between the five Iranians detained in Iraq and the Britons' release.