"Thailand was disappointed with the decision of the Myanmar government to extend Aung San Suu Kyi's house arrest," he said.

The foreign ministry said in its statement that the release of the democracy icon would have ensured "inclusiveness in the national reconciliation process and democratization of Myanmar."

The Nobel peace laureate must spend another year under house arrest at her Rangoon lakeside home after police sources confirmed Friday that military rulers had ordered the move.

The extension drew a sharp rebuke from around the world, particularly from the European Union and the United States, Burma's fiercest critics and which currently have economic sanctions against the regime.

But the impact of the sanctions has been weakened as Burma's energy-hungry neighbours such as Thailand, China and India spend billions of dollars for a share of its vast natural resources, which include oil and gas.

Thailand currently imports about 20 per cent of its gas from Burma, and maintains close ties with its neighbour to the west.

Since overthrowing the elected government of Thaksin Shinawatra last September, Thailand's junta has also faced uncomfortable comparisons with the military leaders next door.

But they insist that, unlike in Burma, the country will return swiftly and peacefully to democracy, with elections promised by the end of the year.

Agence France-Presse