The first Vietnamese President to visit the United States since the end of the Vietnam war 32 years ago has set off from Hanoi.
The focus of the trip will be trade.
Nguyen Minh Triet is expected to ask for what he calls “equal and fair” treatment in commercial relations between the two countries.
One-party, communist-ruled Vietnam joined the World Trade Organisation in January, and wants its goods to be able to enter the US market without unjust restrictions. It is also looking to attract investment, especially in the high-tech sector.
In a meeting on Friday Nguyen and President Bush are expected also to discuss mutual humanitarian complaints.
The US has concerns over human rights and the imprisonment of political opposition.
Hanoi is seeking compensation for victims of the poisonous Agent Orange, used by US and South Vietnamese troops during the war.