BOSTON - The United Nations expert on human rights in Burma said on Monday he would visit the reclusive military-ruled Asian country next month to look into its fierce crackdown on pro-democracy protests.

U.N. special rapporteur Paulo Sergio Pinheiro welcomed the junta's decision to let him in, calling it "an important sign that the government wants to engage again in constructive dialogue with the U.N. and the Human Rights Council."

Pinheiro told Reuters he believed last month's suppression of demonstrations, which were led by Bhuddist monks in several major cities in the impoverished Southeast Asian state, killed many more people than officially acknowledged.

In a letter to Secretary-General Ban Ki-moon on Friday, which was made public on Monday, Foreign Minister Nyan Win suggested that Pinheiro visit Burma before a summit of the Association of South East Asian Nations (ASEAN) opening on Nov. 17 in Singapore.

It will be his first visit to the country in four years.

Pinheiro, a Geneva-based Brazilian law professor who reports to the U.N. Human Rights Council, visited Burma six times after being asked to check on its human rights performance in 2000. But he has not been allowed back since November 2003, despite repeated requests.

Pinheiro welcomed the development. "I am very glad. It's positive news," he said by telephone from Rhode Island, where he is participating in an academic panel at Brown University. he told Reuters.

RISING PRESSURE

Since the crackdown, Burma's ruling military junta has faced international pressure, including from its main ally China, to make concessions to democracy activists led by Nobel prize-winner Aung San Suu Kyi.

It allowed a visit by U.N. Burma envoy Ibrahim Gambari at that time and is being pushed to admit him again quickly.

U.N. High Commissioner for Human Rights Louise Arbour told reporters in Ottawa, "We have to find out what has happened to these people who demonstrated. Where are they? How many -- credibly -- have been killed?"

"How many are still detained (and) under what conditions? So I really hope that collectively we'll be able to persuade the government of Burma to cooperate," she said.

Pinheiro said he planned to fly to Bangkok on Oct. 29 and visit Yangon by early November.

Burma's generals say 10 people were killed in September's crackdown. The protests were the biggest challenge to 45 years of unbroken military rule in the former Burma since 1988, when some 3,000 protesters were believed killed by soldiers.

"That number is quite low," Pinheiro said of last month's official death toll. "I am convinced that the number of the prisoners and the deaths are larger than the numbers estimated by the government," he said.

He said he has received conflicting reports on the number of people who were detained.

A 19-page report Pinheiro plans to present to the United Nations on Wednesday estimates Burma held nearly 1,200 political prisoners as of July 27, up from 1,100 in 2005.

Pinheiro cautioned that Burma's hand-picked commission announced last week to draft a new constitution could founder unless it includes Suu Kyi's National League for Democracy.

"If the commission is composed just of government people the problem will continue. How are you going to make a decision about democracy without the participation of the NLD?"

The military has run the country since 1962, refusing to hand over power even after the National League of Democracy overwhelmingly won a general election in 1990.