The U.N. special envoy for Burma will leave New York Wednesday on his third trip to the military-ruled country.
Ibrahim Gambari is expected to arrive in Rangoon Thursday to resume mediation between the government and the country's opposition.
U.N. spokeswoman Michele Montas has said Gambari expects to stay in the country "as long as necessary."
Gambari met last week with leaders in Beijing, Jakarta, Singapore and Tokyo as part of his efforts to promote democratization and national reconciliation in Burma.
The U.N. envoy has said that Burma's recent announcement of a timetable for a constitutional referendum and elections was a positive sign.
Burma's military leaders announced in early February, plans to hold the referendum in May and general elections in 2010.
The draft constitution would bar pro-democracy leader Aung San Suu Kyi from the elections, a move that has triggered criticism from regional leaders and the United States.
Burmese officials say she is not eligible because she was once married to a foreigner, a British citizen who died of cancer in 1999.
Aung San Suu Kyi and her National League for Democracy won Burma's last general elections in 1990.
The country's ruling generals have refused to recognize the results of those elections and have kept the Nobel laureate under house arrest for 12 of the past 18 years.