Burma's ruling generals have retreated further into isolation by forcing a frustrated United Nations envoy to quit and shunning neighbouring nations' attempts to push for reforms.

The departure of Razali Ismail, who has been denied entry to the country for almost two years, comes at a critical time for the secretive regime which is about to be the subject of a formal briefing at the UN Security Council.

Its one-time supporters in the region have taken a tough new stance, with the 10-nation Association of Southeast Asian Nations (Asean) demanding steps towards democracy and the release of opposition leader Aung San Suu Kyi.

At a summit here last month they secured an agreement for Malaysian Foreign Minister Syed Hamid Albar to visit Burma in January to check on the pace of promised reforms, only to be told last week that it had other priorities.

"I think it does not reflect well. It may be sending a wrong message to the international community, this is our concern and I have conveyed those concerns," Syed Hamid told AFP .

"I don't think it's good for Myanmar to be isolated. This is what Asean is trying to do, to encourage it to interact. But we need to know what is happenning," he said, using the junta's new name for the country.

Syed Hamid said he hoped the visit would go ahead in late February or early March and that he was insisting on seeing Aung San Suu Kyi, who is being held under house arrest at her Rangoon home.

The minister agreed that Razali, a former Malaysian diplomat, had "no choice" but to resign after being frozen out for so long, and that with his departure "the presure on Myanmar is going to be greater".

Burma to be pariah state

Razali was appointed as the special representative of UN chief Kofi Annan in 2000, in a last-ditch move as the world body prepared to officially declare Burma a pariah state.

His swift success in brokering landmark contacts between Aung San Suu Kyi and the ruling generals generated high hopes that Burma was about to emerge from four decades of military rule.

The Nobel peace laureate's release from house arrest in May 2002 only heightened those hopes, but they were dashed when she was taken into custody a year later after clashes between her supporters and a junta-backed mob.

The regime later announced it was holding a national convention to draft a constitution under a "roadmap to democracy" which has been greeted with widespread scepticism by the international community.

Aung San Suu Kyi's party, the National League for Democracy which won 1990 elections in a landslide but was never allowed to govern, is boycotting the process because of her continued detention.

Abdul Razak Baginda from the Malaysian Strategic Research Centre said that by forcing Razali to resign and turning its back on the Asean initiative, Burma was "digging in" and cutting off links its few friends in the world.

"It was Asean that provided them with a window to the world and now the window is slowly shutting," he said. "Especially at the last Asean summit, it was very clear Asean as a whole is unhappy with Myanmar."

Generals stonewalling?

Calls for Burma to be excluded from the regional grouping will now grow louder after the generals showed their disdain by brushing the Syed Hamid visit aside, he said.

"Myanmar is a constant embarrassment to Asean ... and it should be bold enough to threaten the suspension of Myanmar's membership," he said.

"Even if it is not effective, Asean will be seen as an effective organisation. Today everyone is laughing at Asean, saying - someone is biting you and you're not biting back."

However, analysts in Rangoon said the Asean initiative was the best hope yet for pressing the military to introduce reforms, and that the generals could be preparing to produce a trump card.

"It could well be the driver needed to break the present political impasse," said one close observer of the military, on condition of anonymity.

He said the junta could be stonewalling as it prepares to come up with a compromise deal, or at least organise a meeting between the Asean mission and Aung San Suu Kyi, breaking her enforced silence of more than two years.