US president Barack Obama has told Burma's junta to free pro-democracy leader Aung San Suu Kyi and other political prisoners, a US official said.
Obama delivered the message during his summit with leaders of 10 south-east Asian nations in Singapore, which included Burma prime minister General Thein Sein.
White House press secretary Robert Gibbs told reporters that Obama called on Burma to free Suu Kyi and other political prisoners, and end oppression of minorities.
He said Obama "brought that up directly with that government", Mr Gibbs said.
Nobel Peace laureate Suu Kyi has been in detention for 14 of the last 20 years.
For decades, Western governments have avoided direct contacts with leaders of Burma because of the regime's poor human rights record and suppression of democracy.
A joint statement to be issued after the summit - the first between a US president and the Association of Southeast Asian Nations - is expected to devote an entire section on Burma, a major irritant in relations between the two sides.
The statement is not expected to contain a US proposal to call for the release of political prisoners, including Suu Kyi.
But a direct appeal from Obama carries more weight as he is the most powerful leader to have conveyed the message directly to a top Burma official.