Bush was scheduled to arrive in Belfast at 6:25 pm (1725 GMT) for his third summit in less than a month with Blair, at a time when forces loyal to Iraqi leader Saddam Hussein appeared to be crumbling in the face of US advances in Baghdad and British successes in Iraq's second city Basra.

Security was tight for the summit hastily announced last week, with police in Belfast responding Monday to three bomb alerts -- including one at the airport where Air Force One was to land.

"What the summit will give us is a chance to take stock of where we are," a spokesman for Blair told reporters in London.

"It seems a lot longer than -- what was it? -- 10 days that we were at Camp David," the presidential retreat outside Washington where Bush and Blair last met, when the war looked bleak in the face of then-stiff Iraqi resistance.

"We will want to... discuss the post-conflict situation in terms of the scale of how we will make the transition to Iraqi rule as quickly as possible," the Blair spokesman said.

Besides Iraq, the two leaders -- meeting at Hillsborough Castle just outside Belfast -- will also discuss the war's impact on the Israel-Palestinian conflict, transatlantic ties and other "strategic" issues, the spokesman said.

With Irish Prime Minister Bertie Ahern on Tuesday, they will also try to exploit the presidential visit to give a boost to the stalled peace process in Northern Ireland.

Bush and Blair broadly agree on the need for the United Nations to endorse a post-war administration in Iraq, but the United States rejects European demands for the UN to play a front-and-center role.

Concern was raised over the weekend when US Deputy Defense Secretary Paul Wolfowitz suggested Iraq might have to remain under US military control for more than six months once Saddam's regime falls.

British Defense Secretary Geoff Hoon told reporters in London on Monday that it was "obviously right" that security in the "immediate aftermath" of the war should be kept in US and British military hands.

But he stressed there must be an "early move" towards Iraq being run by Iraqis -- both because that would be "right and proper", and because Britain did not want to keep troops in Iraq longer than needed.

US State Department number two Richard Armitage on Monday played down the reported US-British split.

"I suspect when our two leaders issue their final communiques from Hillsborough Castle in Northern Ireland, Great Britain, you will find that there is less difference than perhaps you might have thought," Deputy Secretary of State Armitage said in an interview with CNN.

But he made clear that Washington had not diluted its contention that, in the early days following the end of the war at least, US forces will play the primary role in controlling the country.

By agreeing to meet Blair in Northern Ireland, Bush is repaying the British prime minister for his support over Iraq. The US president will endorse Anglo-Irish efforts to end three decades of sectarian strife and bloodshed in the province.

Thursday is the fifth anniversary of the Good Friday accords between leaders of the pro-British Protestant majority and the republican Catholic minority.

It is also the deadline set by Blair and Ahern for drawing up proposals to revive the peace process, currently stalled amid a climate by mistrust between Protestants and Catholics.

A sour note was sounded by Gerry Adams, head of the republican Sinn Fein party, who criticized Monday what he called the insensitivity of holding a war summit which discusses the Northern Ireland peace process "in the margins."

Adams, whose Sinn Fein opposes the war in Iraq, said it appeared the peace process was being used as a "stage or as a prop."

Thousands of anti-war protesters were, meanwhile, expected to demonstrate at Hillsborough Castle.

SPACE.WIRE