New British Prime Minister Gordon Brown will be walking a political tightrope over the coming hours, by seeking to cement positive relations with the USA, while staking out his own international policy platform.
Mr Brown emphasised in a public statement that the world owes a debt to the United States for its leadership in the fight against international terrorism.
He also described the link with the US as the UK's "most important bilateral relationship" ahead of his first talks with President George Bush.
However a junior foreign office minister has alreday suggested that the two countries will no longer be "joined at the hip" on foreign policy, and has commended bridge-building rather than bombing as a way forward in the global arena.
The PM's spokespeople have said that there is no inconsistency in the line the government is taking,but analyts suggest that Brown is playing a subtle game of affirmation and change together.
He also knows that Mr Bush's political star is waning, both domestically and internationally, with the end of his tenure in 2009 now in sight.
Mr Brown arrived at Andrews air force base near Washington DC this evening (Sunday 29 July 2007).
Commentators and diplomats, as well as politicians on boths sides, will be looking for signs of the Brown administration distancing itself from the USA during the trip.
Both Mr Brown and Mr Bush are active Christians. But their understanding about the way that convictions should impact public life and political policy are likely to push in different directions.
Among Mr Brown's advisors are Sojourbers/Call To Renewal evangelical social activist Jim Wallis, and British Chief Rabbi Jonathan Sachs, a eading moral thinker.