President Bush warned Iran on Wednesday of "serious consequences" if it attacked U.S. ships in the Gulf.
"My advice to them is don't do it," Bush said at news conference in Israel.
Bush's warning came days after Washington said Iranian boats aggressively approached three U.S. Naval ships in the Strait of Hormuz, a major oil shipping route off Iran's coast, and threatened that the ships would explode.
"We have made it clear publicly and they know our position, and that is there will be serious consequences if they attack our ships, pure and simple," Bush said.
Iran called video and audio released by the Pentagon showing Iranian Revolutionary Guards boats confronting the warships as "fabricated," a state-run television station reported.
"The footage released by the U.S. Navy was compiled using file pictures and the audio has been fabricated," the English-language channel Press TV quoted an official in the Revolutionary Guards as saying.
The report did not give the name of the Revolutionary Guard figure and did not offer more details about how the official knew the footage was "fabricated."
The Pentagon on Tuesday released a four-minute, 20-second video that included audio showing small Iranian boats swarming around U.S. warships in the Persian Gulf. In the recording, a man speaking in heavily accented English threatened, "I am coming to you. ... You will explode after ... minutes."
The Iranian boats appeared to ignore repeated warnings from the U.S. ships, including horn blasts and radio transmissions, according to the video, which was shot from the bridge of the destroyer USS Hopper.
From the Hopper, after spotting the approaching Iranian boats, a U.S. Navy crew member says over the radio: "This is coalition warship. I am engaged in transit passage in accordance with international law. Intend no harm."
Bush blasts 'provocative act'
President Bush on Tuesday denounced the incident as a "provocative act."
The audio and video recordings were made separately but were pulled together by the Navy. Often uneven and shaky, the video condenses what Navy officials have said was a 20-minute or so clash.
The top Navy commander in the Gulf has said the Iranian fleet of high-speed boats charged at and threatened to blow up the Navy convoy as it passed near but outside Iranian waters on Sunday. The Iranian fleet "maneuvered aggressively" and then fled as the American ship commanders were preparing to open fire, Vice Adm. Kevin Cosgriff said. No shots were fired.
In Tehran, Iran's Foreign Ministry has suggested that the Iranian boats had not recognized the U.S. vessels. Spokesman Mohammed Ali Hosseini played down the incident.
"That is something normal that takes place every now and then for each party," he told the official Islamic Republic News Agency.
On Wednesday, Iran's Defense Minister Mostafa Mohammad Najjar reiterated that the incident was not unusual.
"The identification of vessels passing through the Strait of Hormuz by Iranian Navy units is a natural occurrence," IRNA quoted Najjar as saying. "Islamic Republic of Iran Navy units always put questions to passing vessels and warships at the Strait of Hormuz and they need to identify themselves. This is in accordance with the normal procedures."
Najjar called Western news reports that the boats threatened to blow up the U.S. warships as "mischief."
"(Iranian) Navy units ... asked them to identify themselves. They responded accordingly and continued their path," IRNA quoted Najjar as saying.
During a White House news conference, Bush called the situation "dangerous."
"They should not have done it, pure and simple," he said. "I don't know what their thinking was, but I'm telling you what my thinking was. I think it was a provocative act."
Cosgriff also has disputed Iran's claims that the incident was a routine encounter, saying Iran's "provocative" actions were "deadly serious" to the U.S. military.