BANGKOK - The head of the Association of Southeast Asian Nations urged Thailand and Cambodia to show "maximum restraint" amid tensions over Phnom Penh's job offer to a fugitive former Thai premier.

ASEAN Secretary General Surin Pitsuwan said the 10-country bloc should not be seen to be divided by the dispute ahead of a historic meeting with US President Barack Obama and regional leaders later this month.

Cambodia and Thailand on Thursday recalled their respective ambassadors after Cambodia appointed Thaksin Shinawatra, who was ousted as Thailand's prime minister in a coup in 2006, as an economic adviser.

Thailand and Cambodia have fought a series deadly clashes on their border since July 2008 in a dispute over land around an ancient Cambodian temple that was granted UN World Heritage Status.

Surin expressed "concern over the escalation of tensions between Cambodia and Thailand, has appealed to both countries to exercise maximum restraint," said a statement issued by the ASEAN Secretariat in Jakarta.

He also urged foreign ministers from the bloc to help the two countries to "settle their bilateral dispute amicably and as soon as possible".

"We in ASEAN cannot afford to be seen as being so seriously divided prior to the upcoming APEC Economic Leaders Meeting and the historic ASEAN-US Leaders Meeting in Singapore this month," it quoted Surin as saying in a letter to regional foreign ministers.

Thailand has accused Cambodia of interfering in its internal affairs by appointing Thaksin, who is living abroad to avoid a two-year jail term for corruption.

Cambodia says Thaksin was the victim of a politically motivated case.

During his time in power, Thaksin was close to Cambodian Prime Minister Hun Sen, who first floated the idea of the adviser's job at an Asian summit in October.

The billionaire tycoon has stirred up a series of protests in recent months against the Thai government. His own allies were forced from government in December 2008 after anti-Thakin demonstrators besieged Bangkok's airports.