The Thai government recalled its ambassador from Phnom Penh on Thursday, following a decision by the Cambodian government to appoint ousted former premier Thaksin Shinawatra as an adviser to the Prime Minister Hun Sen.

The withdrawal, ordered by Thai Prime Minister Abhisit Vejjajiva, was another blow to worsening relations between the two countries, which both have troops amassed along an already contentious border.

“We have recalled the ambassador as the first diplomatic retaliation measure to let the Cambodian government know the dissatisfaction of the Thai people,” Thai Prime Minister Abhisit Vejjajiva was quoted saying in Bangkok.

“Last night’s announcement by the Cambodian government harmed the Thai justice system and really affected Thai public sentiment,” Agence France-Presse quoted Abhisit saying.

Officials announced on Wednesday that King Norodom Sihamoni had approved Thaksin as an economic adviser to Hun Sen, who has said he would welcome the fugitive official in spite of an extradition treaty with Thailand.