Thailand defended its deportation of 40 Uyghur detainees to China last week as the “best solution” to avoid a backlash from Beijing, after a rights group said the move violated international law and the returnees could face torture.

Thailand's deportation of 40 Uyghurs to China last week was in the Southeast Asian country's best interest due to the possibility of retaliation from Beijing if the group was sent elsewhere, a Thai minister said on Thursday.

The State Department says the United States and other countries made repeated offers to Thailand to resettle more than three dozen Uyghur men before they were deported back to China, where rights groups fear they may face torture and other abuse.

Rights groups criticized the Thai government for sending the Uyghurs, a persecuted Muslim minority, back to China, where they face the risk of torture and imprisonment.

The secret deportation by Thailand of dozens of Uyghur men to China that has sparked international condemnation is a diplomatic win for Beijing and a snub to the United States and the United Nations,

Canada and the United States offered to resettle 48 ethnic Uyghurs held in detention in Thailand over the past decade, sources told Reuters, but Bangkok took no action for fear of upsetting China, where they were covertly deported last week.

The Chinese embassy in Thailand has confirmed that a group of Uyghur men detained in Thailand for more than a decade have been deported to China.

The government chose not to send the asylum seekers to a third country in order to avoid retaliation from Beijing, diplomats and opposition lawmakers say.

China has assured Thailand that 40 Chinese Uyghurs it returned on Thursday would be looked after, Thailand's defence minister said, confirming a secretive pre-dawn deportation that the United Nations and human rights groups condemned.

The Thai government violated domestic and international law by forcibly sending at least 40 Uyghur men to China, where they could face torture, arbitrary detention, and long-term imprisonment.