Bangkok, Thailand (CNN) -- Relations between Cambodia and Thailand took a further turn for the worse Tuesday, after ousted Thai Prime Minister Thaksin Shinawatra arrived in Phnom Penh to begin his new job there.
Thaksin arrived in Cambodia Tuesday to begin his first day as an economic adviser, a move that has infuriated Thailand.
In response to the relationship with Thaksin, Thailand has suspended its cooperation with Cambodia, a Thai government official said Tuesday.
Thailand has also suspended a memorandum of understanding with Cambodia, an agreement that governs an overlapping waterway between the two countries, said Panitan Wattanayakorn, a Thai government spokesman.
Thai officials also plan to send out an extradition request to Cambodia for Thaksin, the spokesman said.
The actions are the latest moves in worsening relations between the southeast Asian countries that were sparked by Cambodia's hiring of Thaksin.
Last week, Thailand withdrew its ambassador to Cambodia and, in response, Cambodia pulled its top diplomat to Thailand.
Cambodian officials said Thaksin arrived Tuesday and had a welcome luncheon with Prime Minister Hun Sen and the two were expected to have a friendly dinner later.
Cambodia had not received extradition papers from Thailand, government spokesman Phay Siphan said.
Thaksin, a billionaire businessman who served two terms as prime minister, was ousted in a bloodless coup in 2006. Thaksin fled Bangkok last year while facing trial on corruption charges that he said were politically motivated.
Though he has fled the country, he remains a controversial figure in Thailand, and there have been violent clashes in the country between pro and anti-Thaksin groups.
CNN's Kocha Olarn contributed to this report.