Ibrahim Gambari (file photo)

The office of the United Nations Secretary-General has announced that special envoy Ibrahim Gambari will meet Burma's top leader, General Than Shwe, Tuesday.

Officials say Secretary-General Ban Ki-moon telephoned Gambari Monday to express support for his mission and that Mr. Ban asked Gambari to call on Burmese authorities to cease repression, release detainees and move toward real democratic reforms.

Hours later, Burma's foreign minister told the U.N. General Assembly meeting in New York that elements inside and outside the country are trying to derail government's move toward democracy.

Minister U Nyan Win also defended the crackdown on what he called "an unruly mob" as essential to restore order and said normalcy has returned to the country.

Earlier in the day, human rights groups throughout Asia issued a call to support a U.N. fact-finding mission and human rights monitoring system in Burma.

In Washington, the State Department said action by Burma's neighbors is critical to force military leaders to end their crackdown on dissent and allow political reform.

U.S. officials did not rule out additional punitive measures against Burmese military rulers but said their options are limited.

London-based human rights group Amnesty International called on the U.N. Security Council to impose an immediate arms embargo on Burma. The group named China and India as Burma's main arms suppliers.

Other human rights groups said they fear the numbers of those detained or killed in last week's crackdown are much higher than figures reported by Burma's military rulers, who said 10 people died.

Buddhist monks led last week's mass demonstrations in Rangoon calling for freedom and democracy in military-ruled Burma.

The streets of Rangoon were reported to be quiet Monday, with security forces maintaining a heavy presence.

Some information for this report was provided by AP.