President Bush gestures as he speaks to members of the coalition forces during a visit to US Central Command at MacDill Air Force Base in Tampa, Florida, 1 May 2007

President Bush says terrorists in Iraq continue to unleash what he calls "horrific acts of violence." But he says coalition forces are making progress in capturing insurgent leaders and disrupting car-bombers.

"There has been a decline in sectarian violence, and in some areas of the capital, Iraqis are returning to their neighborhoods with an increased feeling of security," said Mr. Bush.

The president spoke to U.S. and allied commanders meeting in the southern state of Florida on the fourth anniversary of his much-publicized appearance on the deck of the aircraft carrier U.S.S. Abraham Lincoln under a banner that read: "Mission Accomplished". At that time, he told sailors they had fought for the cause of liberty and world peace, freeing Iraq and making America more secure.

"Major combat operations in Iraq have ended. In the battle of Iraq, the United States and our allies have prevailed," he said.

White House spokeswoman Dana Perino says the United States and its allies did prevail in terms of toppling the Iraqi army and Saddam Hussein.

But opposition Democrats have repeatedly seized on that speech as a sign that the president failed to understand the challenges ahead. They want U.S. troops to withdraw from Iraq starting in October and have linked that demand with legislation funding the war.

Perino says it is a "trumped-up political stunt that is the height of cynicism" for Democrats to send the president the funding bill on this fourth anniversary of what has come to be known as the "Mission Accomplished" speech.

The president says he will veto the measure because a timetable for troop withdrawal would embolden the enemy and make America appear weak.