The United States has condemned the Burmese military government's latest crackdown on opposition leader Aung San Suu Kyi and her National League for Democracy party, the NLD. The State Department is calling for the immediate release of the Nobel peace laureate and top associates from detention.

The United States has strongly supported U.N.-led efforts at political reconciliation in Burma, and it is condemning the detention of Aung San Suu Kyi and other leaders of her party as a "significant step back" for the military government and for the Burmese people.

The military leaders in Rangoon took sweeping measures against the opposition after a violent clash Friday between supporters of Ms. Aung San Suu Kyi and a pro-government group in northern Burma that reportedly left four people dead and injured dozens more.

The government took the democracy leader into what was termed "protective custody" shortly after the clash, and later confined other NLD officials and closed party offices as well as university campuses seen as opposition strongholds.

In a written statement volunteered to reporters, State Department spokesman Philip Reeker said the crackdown on the NLD hinders national reconciliation and a peaceful transition to democracy and is inconsistent with the will and the rights of the Burmese people.

Mr. Reeker said a government that does not allow peaceful political expression cannot be counted as a responsible member of the international community.

He said the United States in concert with other concerned countries, including other members of the U.N. Security Council, is considering "all measures available" in efforts to foster a transition to democracy in Burma.

The move against the Burmese opposition came just days before the United Nations special envoy for Burma Razali Ismail was to return to Rangoon for another attempt to re-start negotiations between Ms. Aung San Suu Kyi and the government.

Spokesman Reeker said the United States continues to support the effort by the former Malaysian U.N. ambassador to encourage Burmese national reconciliation, and urges military authorities to "take advantage" of his visit, due to begin Friday, to "reverse this recent setback" and make progress.

Ms. Aung San Suu Kyi's party won national elections in 1990 but was barred from taking power. She spent most of the time since then under house arrest, and her release a year ago raised hopes of a settlement.

In comments to reporters accompanying him to Middle East peace talks in Egypt Monday, Secretary of State Colin Powell said the United States had relayed its call for Ms. Aun San Suu Kyi's release to the Burmese government through diplomatic channels.

Mr. Powell said Burmese authorities asserted that that they acted to protect her from last week's disturbance, and said if that is the case, she should be promptly released.

The Burmese political situation will be a key issue later this month, when the Secretary of State is expected to join other Pacific-region foreign ministers for a dialogue with their counterparts from ASEAN, the Association of Southeast Asian Nations, in the Cambodian capital, Phnom Penh.