United Nations Secretary-General Ban Ki-moon will travel to Burma later this week to press the military government to release all political prisoners and start a dialogue with the opposition.

U.N. spokeswoman Michele Montas told reporters Monday that Mr. Ban is due in Burma on Friday, following a trip to Japan. His special envoy for Burma, Ibrahim Gambari, concluded a two-day visit to the east Asian country on Saturday.

The Nigerian diplomat did not meet with jailed pro-democracy leader Aung San Suu Kyi. It is not clear whether the U.N. chief will be able to meet with her.

Burma's highest court on Monday rejected an appeal to reinstate two defense witnesses at Aung San Suu Kyi's trial. She is accused of violating her house arrest by letting American John Yettaw stay overnight after he swam to her home uninvited last month.

Nyan Win, a spokesman for Aung San Suu Kyi's National League for Democracy party, said the court decision demonstrates that the trial is rigged. The opposition leader has been permitted only one witness, compared to 14 witnesses for the prosecution. Win said the opposition welcomes the U.N. efforts on behalf of democracy.

The international community has denounced the trial as a sham and is demanding her release.

The trial is being held at a high-security prison, Insein, outside Rangoon.

Aung San Suu Kyi has spent 13 of the last 19 years under house arrest. If convicted, she faces five years in prison.

Some information for this report was provided by AFP and AP.