A decade of economic sanctions has failed to push military-ruled Burma (renamed Myanmar by the military junta) towards democracy and nations have to find another way to engage the country, said a top Southeast Asian official.

The United States and the European Union earlier this year renewed sanctions first introduced about 10 years ago against Burma over rights violations, including the continued detention of pro-democracy leader Aung San Suu Kyi.

But the secretary general of the Association of Southeast Asian Nations, Ong Keng Yong, said sanctions were not working since member Burma was largely immune to them.

"These kinds of sanctions and isolation does not work ... They are happy being isolated because they are left alone to do whatever they want to do," Ong told reporters at the sidelines of the Asia Oil and Gas Conference here.

"What we are saying is perhaps we should look at some other ways of doing it instead of just (keeping) on applying sanctions," he said.

Burma's junta extended Aung San Suu Kyi's house arrest by another year late last month, prompting condemnation from the United States, the United Nations and European and Asian nations.

The 61-year-old Nobel peace laureate has spent more than a decade confined to her home. Her party won a landslide victory in 1990 elections but the junta never allowed it to take office.

Friendly neighbours

"Even if you pull out everybody, economic investors, from Myanmar, they are not going to collapse simply because their two big neighbours will be ready to sustain them," Ong said in apparent reference to China and India.

China and India have been criticised for keeping silent over Burma's rights abuses.

Ong also said Burma would never allow itself to be seen as bowing to international pressure to release the democracy icon.

"That will never happen. You have to ... find a face-saving way out," he said.

Burma, which joined Asean in 1997, has embarrassed the regional bloc by steadfastly refusing to introduce democratic reforms.

Ong said the 10-member bloc would continue to engage Burma, arguing economic development and growth may help the country to come around.

"This is the sad thing about Asean, the only leverage we have is that Myanmar is a member of Asean. We hope to pressure it to do more," he said.

Ong said Asean foreign ministers would talk to their Burma counterpart about Aung San Suu Kyi in a meeting scheduled for July in Manila, although it would not be the main item on the agenda.

"Asean does not want to talk about punitive measures, we have other ways to operate but everybody knows we have to make some progress and this time I hope Mynamar can respond," he said.