The secretary-general joined politicians and human rights activists from around the world in sending greetings to Aung San Suu Kyi, as she prepares to celebrate her 60th birthday. But in carefully worded response to a reporter's question, Mr. Annan avoided mentioning the detained Burmese opposition leader by name.
"Let me first wish a Happy Birthday. It is unfortunate she is celebrating it under the circumstances that one would not have wished for her, a leader of her party, and I wish she were out amongst her people and her supporters pushing for stability and democracy and democratization of her society," he said.
Mr. Annan said he has been in touch with the head of Burma's military junta to seek Aung San Suu Kyi's release.
"I have had a chance to raise this issue with General Than Shwe and I would urge him to release her and let her join her party and join the national dialogue and national reconciliation," he said.
Political activists, performers and governments throughout the world are increasing pressure on Burma to release Aung San Suu Kyi. Britain and the United States have been among the most vocal in condemning her detention.
British Foreign Secretary Jack Straw issued a statement in London condemning what he described as Burma's "appalling" human rights record.
Congressman Tom Lantos has said he will lead a demonstration to demand Aung San Suu Kyi's release Friday in front of the Burmese embassy in Washington . Other protests are planned at several other Burmese embassies worldwide.
Despite international pressure, the Nobel laureate has spent nine of the last 16 years behind bars or under house arrest.
Burma's military, in power since 1962, says it remains committed to a political transition, including a new constitution that would lead eventually to greater freedoms.
A U.N. human rights envoy who had visited Burma six times before November, 2003 called this week for the military authorities to clarify the country's political direction.
After his last visit, human rights envoy Paulo Sergio Pinheiro sharply criticized the detention of 1,300 political prisoners and expressed skepticism about the government's reform plans. He has not been allowed to return since.