The top United Nations human rights envoy arrived in Burma Monday for a five-day visit to evaluate progress on human rights in the military-ruled nation.
Tomas Ojea Quintana is expected to urge the military government to allow opposition and ethnic political parties to participate in upcoming elections.
Quintana has said he also wants to meet Nobel Peace laureate Aung San Suu Kyi, who remains under house arrest.
Quintana's visit follows Saturday's release from detention of Tin Oo, the vice-chairman of Burma's opposition National League for Democracy.
The 83-year-old retired general and former defense minister was released after seven years of detention.
Tin Oo said Sunday he is not happy with his freedom as long as other political prisoners are being held by Burma's military government.
Some information for this report was provided by AP.