State Department spokesman John Kirby says that the action "runs counter to Thailand's international obligations" and the US is deeply concerned about the protection of asylum-seekers there.
Thailand's decision to send the minority Muslims back to China has drawn harsh criticism from the UN refugee agency, which called it a "flagrant violation of international law."
Kirby is urging Thailand to allow remaining Uighurs to depart to a country of their choice, and he's calling on China to give due process to those deported.