The United States intends to pursue a UN Security Council resolution aimed at highlighting complaints about continuing repression and other problems in Myanmar, the State Department said on Wednesday.
The economic, political and public health situation in Myanmar, also known as Burma, "has deteriorated to the point where the regime's activities and repression of political rights now pose a threat to the stability, peace and security of the region," spokesman Sean McCormack said in a statement.
It was issued four days after Myanmar's authorities decided to extend the detention of pro-democracy activist Aung San Suu Kyi.
McCormack called Suu Kyi "a great champion of democracy" and said her continued detention was unjustified.
Suu Kyi, leader of the National League for Democracy, has spent about 10 of the last 17 years in detention, and her most recent sentence expired on Saturday.
A government official said the order had been extended for one year.
UN Secretary-General Kofi Annan and officials from Myanmar's neighbors expressed disappointment at Myanmar's decision.
Two weeks ago, President George W Bush renewed financial and other sanctions against Myanmar that have been in effect since 1997, when a state of emergency was declared between the United States and Myanmar.