WASHINGTON — President Bush said Tuesday that Iran's confrontation with the U.S. Navy ships in the Persian Gulf was a "provocative act."

"It is a dangerous situation," he said in a White House news conference. "They should not have done it, pure and simple. . . . I don't know what their thinking was, but I'm telling you what my thinking was. I think it was a provocative act."

The top U.S. Navy commander in the area said an Iranian fleet of high-speed boats charged at and threatened to blow up a three-ship U.S. Navy convoy passing near but outside Iranian waters on Monday, as they headed into the Persian Gulf through the Strait of Hormuz. The Iranian fleet "maneuvered aggressively" and then vanished as the American ship commanders were preparing to open fire, said Vice Adm. Kevin Cosgriff. No shots were fired.

In Tehran, Iran's Foreign Ministry suggested 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 state news agency IRNA.

"My message today to the Iranians is they shouldn't have done what they did," Bush said.

Bush also said that a recent intelligence assessment on Iran, which determined that Tehran had halted its nuclear weapons program in 2003, sent a "mixed signal" to the international community on U.S. policy.

"Iran was a threat. Iran is a threat. And Iran will continue to be a threat if they are allowed to learn how to enrich uranium," he said.

The incident came as Bush got ready to leave Tuesday evening on an eight-day Mideast trip designed in part to counter Iran's influence in the region. Bush is expected to discuss the U.S. posture toward Tehran with Arab allies also worried about Tehran's desire for greater regional power.

"It's just another point of reference for people in the region who are concerned about the behavior of Iran," Perino said of Monday's skirmish. But, she said that while Iran will be "part of the discussion" during Bush's travels, "it's certainly not the main reason for the trip."