"I deplore the lack of follow-up on previous recommendations to protect the rights of Uyghurs and other Muslim minorities in Xinjiang, and of Tibetans in their regions," Volker Turk told the UN Human Rights Council in an update on rights situations around the world.

"This includes labour issues and religious and cultural freedoms," he said, also voicing concern "by the intensified repression of Protestant communities".

An explosive 2022 report by Michelle Bachelet, Turk's predecessor as UN high commissioner for human rights, cited possible "crimes against humanity" in Xinjiang.

The report, which was criticised by China, highlighted "credible" allegations of widespread torture, arbitrary detention and violations of the religious and reproductive rights of Uyghurs and other Muslim groups.

Since taking the helm of the UN rights office shortly after Bachelet's report was published, Turk has faced calls from rights groups to put more pressure on China.

In his address Friday, Turk also called on China "to stop using vague criminal administrative and national security provisions to suppress the peaceful exercise of fundamental rights" in the country.

He did not provide examples but earlier this month the UN rights chief highlighted the use of a Beijing-imposed national security law to sentence Hong Kong pro-democracy media tycoon Jimmy Lai to 20 years behind bars.

"I urge them to release all those arbitrarily detained," he said.