The Thai government has suffered intense criticism from around the world for its decision to hand over at least 40 Uyghurs, who were flown by special plane to China's northwestern Xinjiang region in late February.

The Uyghurs had spent years languishing in Thai detention facilities after fleeing China more than a decade ago.

On Friday US Secretary of State Marco Rubio announced visa restrictions on an unspecified number of former or current officials from Thailand involved in the deportation.

Thailand's foreign affairs ministry said in a statement on Saturday it noted the US decision adding it had "received assurances from the Government of China concerning the safety of the Uyghurs".

It said Thailand "will continue to follow up on the well-being of this group".

Thailand is the oldest US ally in Asia but maintains friendly relations with Beijing.

"Thailand has always and will continue to value the long-standing and close treaty alliance with the United States," the statement said.

The United States accuses China of genocide over its mass camps for Uyghurs, a mostly Muslim minority in the northwestern Xinjiang region.

China rejects the accusations and says it is providing vocational education to improve Uyghurs' future.