Tony Blair is heading for his first summit with US President George W Bush.
He is determined to build a good working relationship after the Premier's close friendship with Bill Clinton.
He is due to hold White House talks with Vice-President Dick Cheney before going to the Presidential retreat at Camp David.
Defence and trade issues are expected to top the official agenda, including America's plans for the controversial "son of Star Wars" National Missile Defence system.
But all eyes will be on the personal chemistry between Mr Blair and Mr Bush.
Mr Blair and his wife Cherie, accompanying him on the visit, became close personal friends of Bill and Hillary Clinton.
Mr Blair, speaking to American reporters before he left London said: "Bill Clinton became a close friend of mine, is a close friend, and always will be. You can be close friends with more than one person."
The British Prime Minister will be questioned about his relationship with Mr Bush on live coast-to-coast American news programmes before heading for Camp David.
Mr Blair is flying into Washington after a brief visit to Canada where he held talks with his counterpart Jean Chretien.