The top US diplomat in Burma is to hold talks with the country's leaders, as a UN envoy prepares to brief the Security Council on his recent visit there.
There are continuing and disturbing reports of human rights abuses in Burma following protests there, a UN envoy has told the Security Council.
Shari Villarosa was invited to meet unspecified leaders and would raise concerns over the military's crackdown on recent protests, US officials said.
Ibrahim Gambari warned Burma's military rulers their actions could have "serious international repercussions".
Later in the day, Ibrahim Gambari will brief the Security Council on his talks with top generals earlier this week.
He was speaking after a four-day visit to Burma, where he met senior generals and opposition leader Aung San Suu Kyi.
There is serious concern over the crackdown, which left at least 10 dead.
Burmese state TV reportedly broadcast an image of Ms Suu Kyi on Friday for the first time in years.
Diplomats fear the death toll is far higher and thousands of protesters are thought to be in detention.
The authorities say 10 people were killed in the crackdown that followed last week's protests.
'Clear message'
But Mr Gambari said he feared the real death toll could be much higher.
Ms Villarosa left early on Friday for the rare meeting with Burma's generals in the remote capital, Naypyidaw.
Earlier, UN Secretary General Ban Ki-moon said the Burmese authorities' use of force on peaceful protesters was "abhorrent and unacceptable".
State department spokesman Sean McCormack said that she would send a "clear message" to the leadership to end the crackdown and engage in dialogue with opposition groups.
But it was not clear who she would meet or what topic the generals who summoned her planned to address.
Her meeting comes ahead of a keenly anticipated briefing by Mr Gambari to the UN Security Council on his dialogue with the military leadership.
Mr Gambari met both General Than Shwe and detained pro-democracy leader Aung San Suu Kyi during his four-day visit to Burma.
He met Ms Suu Kyi twice, prompting speculation that he might have been carrying messages between the two sides.
In a surprise move on Thursday, Gen Than Shwe agreed in principle to meet the opposition leader, who has been held under house arrest for 11 of the past 17 years.
But the general, who has not shown interest in dialogue in the past, insisted on preconditions to any talks, state media reported.
Ms Suu Kyi would have to drop her support for international sanctions and abandon her confrontational attitude, the reports said. HAVE YOUR SAY International pressures don't affect these devils. Only innocent citizens suffer Peter S H Chen, Singapore Send us your comments
Members of her party said this amounted to asking her to confess to offences she has not committed.
Aung San Suu Kyi has been saying for more than a decade that she would talk to anyone to try to bring peace and stability to the country, the BBC's Chris Hogg in Bangkok says.
But she is also uncompromising in her dealings with the military government when she feels like they are trying to damage her, he adds.
Previous attempts to build dialogue between the military and Aung San Suu Kyi - who is still the pre-eminent symbol of Burma's democratic movement - have come to nothing.
Quiet streets
In Burma, state media has said that 2,093 people were arrested during the crackdown on the protests.
Buddhist monks spearheaded the pro-democracy protests
It said 692 people had already been released after signing a declaration that they would not take part in any future rallies.
However, BBC sources in Burma say as many as 10,000 people - many of them monks who led the marchers - have been rounded up for interrogation in recent days.
Dozens are feared to have died during the suppression of the protests, which were triggered by a government decision to raise the price of fuel.
Residents of the main city, Rangoon, say the streets are now quiet during daylight hours, with the police and army keeping a low profile.
But during the overnight curfew, they say raids by the security forces continue.
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