French President Nicolas Sarkozy has begun his first official visit to the United States since coming to power.
He is due to address a joint session of Congress and hold talks with US President George W Bush.
Mr Sarkozy will also present the Legion of Honour, France's highest award, to several US citizens.
The two presidents are expected to discuss the issue of Iran's nuclear ambitions, about which officials say they are in close agreement.
Correspondents say the visit will help heal the divisions between the two countries that came to a head when France opposed the US invasion of Iraq in 2003.
The French president, who was elected in May and visited the US on holiday in August, is seen as more pro-American than his predecessor Jacques Chirac.
The BBC 's Justin Webb in Washington says that the Bush White House increasingly sees President Sarkozy as its principal ally in efforts to halt Iran's nuclear programme.
However the French AFP news agency says there will be some areas of disagreement.
In his address to Congress, President Sarkozy will touch on environmental issues, and is expected to call on the US to take the lead in the fight against climate change.
Ahead of the meeting, he voiced concern about the weakness of the US dollar, saying "a strong economy should have a strong currency. You don't need a dollar too weak."