Standing in the freezing cold at Belfast International Airport, there were a few signs that the most powerful man in the world was on his way.

Scores of men in dark suits and sunglasses were talking into their sleeves, scouring with a measured degree of suspicion the melee of journalists and photographers grappling for position.

Dozens of police officers were milling around the runway perimeters, casing the outlying area for unusual activity, and helping to keep the media behind the 'black line'.

"Cross that at your peril," boomed an NIO press officer, pointing up at snipers.

Bush's arrival — at 2.45pm — was a long time coming for the media who had picked up their special passes at the Hilton Hotel in Templepatrick before 10am, before being taken to the airport by bus, via the RAF entrance.

Security — including bags and body searches — was tight from start to finish, and en route the road leading up to the base was dotted with signs that read 'Response level heightened'.

The first flurry of real activity began shortly after 2pm, with the arrival of Prime Minister Gordon Brown and his wife Sarah on a twin engine Turboprop plane that touched down in the army air corps section of the airport.

Fifteen minutes later the president's support plane, a Boeing 757-type, landed, bearing his impressively large entourage.

As we waited patiently for the president's arrival, a convoy of nine cars drew up to the side of the runway around 2.30pm, causing a small ripple of excitement among the waiting press.

Suddenly, the unmistakeable sound of Air Force One pierced the air, signalling the arrival of the blue and white presidential aircraft, as it glided down, coming to a halt about 150m away from the riser.

Moments later, the president of the USA emerged from its front door and waved quickly, before making his way down the stairs, alongside wife Laura.

Greeted by a line-up who hailed from the convoy, including Gordon Brown and his wife Sarah, Secretary of State Shaun Woodward and his wife Camilla, British Ambassador to the USA Sir Nigel Sheinwald KCMG and his wife, RAF Station Commander Captain David Stubbs and his wife Kath, Lord O'Neill, Lord Lieutenant of Co Antrim and American Consul General Dr Susan Elliot, the last stop on the final leg of Mr Bush's farewell tour had officially begun.

The President glanced around, waved to the local press — and his own media corps — and stepped into the presidential limousine, a mere ten minutes after arriving.

And as a cavalcade of 48 cars set about the onward journey, the local media were left to marvel at the magnificence of Air Force One, while the Secret Service men continued to eye us all with that same suspicion.