Annan appeals for a prompt return to civilian, democratic rule and the "holding of new elections as quickly as possible," the UN chief's spokesman said in a statement.

"The secretary-general is following with concern developments in Thailand after the overthrow of the elected government there," the statement said.

"The secretary-general pays tribute to the progress the people of Thailand have made in recent years ... in establishing and strengthening democratic institutions. He expresses his profound hope that those efforts will resume very soon," the statement said.

After a bloodless coup d'etat, Thai prime minister Thaksin Shinawatra was ousted, and that General Surayu Zhulanong, a privy counselor to the King of Thailand, would become the new prime minister of a transitional military government.