WASHINGTON - Speaking aboard a carrier whose warplanes helped destroy Saddam Hussein's regime, President Bush declared last night in front of thousands of cheering sailors that major combat in Iraq has ended but that the U.S.-led success in Iraq was just one phase in a broad war on terrorism.

"In the battle of Iraq, the United States and our allies have prevailed," the president said, standing on a stage set on the enormous flight deck of the USS Abraham Lincoln, which is returning home after a 10-month mission. "And now our coalition is engaged in securing and reconstructing that country."

Bush's speech, interrupted frequently by spirited ovations from the sailors, followed his screeching landing on the Lincoln in an S-3 Viking jet.

His arrival, with Bush emerging from the plane in a flight suit, afforded him a moment of grand visual imagery that serves White House efforts to cast him as a successful wartime leader.

In his 22-minute speech, the president linked the Iraq war to the larger and continuing battle against global terrorism.

He evoked images of the Sept. 11 attacks and issued another warning to nations that support terrorists or try to build chemical, biological or nuclear weapons.

"Any outlaw regime that has ties to terrorist groups, and seeks or possesses weapons of mass destruction, is a grave danger to the civilized world and will be confronted," he said.

He made no mention, however, of Iran or North Korea, the two countries he had linked last year with Iraq as part of an "axis of evil."

While effectively declaring the war in Iraq over, the president cautioned that there is "difficult work to do," noting that parts of that country "remain dangerous" and that there are still Iraqi leaders who must be brought to justice.

He did not mention that Hussein has yet to be found or that none of Hussein's weapons of mass destruction - the principal justification for the U.S. invasion of Iraq - has been discovered.

Bush noted that the al-Qaida terrorist organization is "wounded, not destroyed." He claimed for the first time, however, that "nearly one-half of al-Qaida's senior operatives have been captured or killed."

The president, a former pilot in the Texas National Guard, briefly took the controls of the jet as it flew about 30 miles from San Diego to the deck of the Lincoln. It was the first time a president had landed on a carrier and spoken to the nation at sea.

Arriving early in the afternoon, Bush jauntily strolled the carrier deck dressed in a green flight suit, smiling broadly, shaking hands, throwing his arm around sailors and posing for countless pictures.

Asked whether he had flown the jet, he replied: "Yes, I flew it. Yeah, of course, I liked it."

Bush, who flew a jet for the first time since his days in the National Guard, said he had piloted the plane for about a third of the 20-minute flight.

"Good job," he said to some of the sailors on the Lincoln. "Great job."

The striking scene, captured on national television, offered an ideal backdrop for a man whose re-election campaign next year is likely to be defined in large part by his leadership in confronting threats to America's security.

The carrier has a crew of more than 5,000, and its warplanes include the Navy's most sophisticated attack jet, the F/A-18E Super Hornet.

The crew members have been at sea for 10 months, the longest deployment for a carrier strike group since the Vietnam War.