The United States has extended sanctions against Burma for a year, saying the constitutional convention organized by the country's military government lacks legitimacy.
In a statement issued Friday, the White House said the convention -- which is aimed at framing a new constitution for Burma -- has not allowed substantive dialogue or full participation by all political groups.
The White House said the ruling military has failed to make progress towards democracy and national reconciliation in the face of growing criticism from Burma's neighbors and the international community.
It also called on the Burmese military to release all political prisoners, including National opposition leader Aung San Suu Kyi, whose National League for Democracy party is boycotting the convention, because she remains under house arrest.
State Department spokesman Richard Boucher said Friday that the assembly taking place outside Rangoon "is not truly representative of the people of Burma."
The government picked most of the delegates to the gathering, which foreign diplomats and human rights organizations have dismissed as a sham.
Reports from the meeting say the Burmese government has issued strict rules about conduct to convention delegates. Participants have been warned not to express disloyalty to the state or discuss topics outside the official agenda. They also are forbidden to walk out on the proceedings.
The code of conduct also dictates that delegates dress appropriately, take baths at reasonable times, and avoid eating junk food.
The convention is supposed to a first step to what the military says will be Burma's eventual transition to democracy.
Information for this report is provided by AP, AFP and Reuters.