Ban: I'm deeply disappointed
Burma's junta has refused to allow visiting UN Secretary General Ban Ki-moon to meet jailed opposition leader Aung San Suu Kyi.
Mr Ban was told of the refusal when he held a second round of talks with military leader Gen Than Shwe.
"I'm deeply disappointed," he told reporters. "I'm very sorry to report to you that this is not possible."
Ms Suu Kyi's trial on charges of breaking the terms of her house arrest was postponed again on Friday.
Mr Ban said Than Shwe had told him during their 30-minute meeting, in the remote administrative capital Nay Pyi Taw, that Ms Suu Kyi was on trial and he did not want to interfere with the judicial process.
The UN leader later left for Burma's main city, Rangoon.
Mr Ban's had a two-hour meeting with Gen Than Shwe on Friday.
A LIFE IN DETENTION
1988: Junta comes to power after crushing pro-democracy uprising
1989: Martial law declared; opposition NLD leader Aung San Suu Kyi put under house arrest
1990: NLD wins elections; result rejected by the ruling junta
1995: Suu Kyi freed from house arrest; movements restricted
Sept 2000: Under house arrest for trying to defy travel curbs
May 2002: Released unconditionally
May 2003: Detained after clash between NLD and junta forces
Sep 2003: Home after surgery, under effective house arrest
UN chief's big gamble
Why is junta afraid of Suu Kyi?
Mr Ban said he had been assured that elections planned for 2010 would be "held in a fair, free and transparent manner".
The UN chief is due to make a speech outlining his vision for Burma later on Saturday.
Ms Suu Kyi, a Nobel Peace laureate, has spent much of the past two decades in prison or under house arrest.
She was transferred from house arrest to prison in May after an American man swam to her lakeside house. She faces up to five years in jail if convicted.
Next year's elections are part of the military government's "roadmap to democracy," but critics say they will be a sham designed to strengthen the generals' four-decade grip on power.
Opposition activists say Ms Suu Kyi's trial is designed to keep her out of the way until after the elections.