United Nations secretary general Antonio Guterres will seek to appoint his Austrian colleague Volker Turk as the next High Commissioner for Human Rights, diplomats and rights groups said on Thursday.

A week after Michelle Bachelet stepped down at the end of her four-year term as rights chief, the UN has yet to officially announce who will replace her.

But multiple sources said that Guterres had notified UN member states late on Wednesday that he wants Turk, a UN veteran who is currently serving as assistant secretary general for policy, in the challenging role.

The 57-year-old Austrian, who has worked within the UN system for more than three decades and worked closely with Guterres back when he headed the UN refugee agency.

The UN General Assembly was expected to address the matter during a meeting later on Thursday or Friday, sources said.

"In all previous appointments, the secretary general's recommended candidate has been approved by consensus," the International Service for Human Rights (ISHR) pointed out in a statement.

Turk will have his work cut out.

Bachelet, a former Chilean president, published a long-awaited report on rights abuses in China's Xinjiang region just minutes before the end of her term, leaving the tricky follow-up job to her successor.

The report urged Beijing to end "discriminatory" practices against Xinjiang's Uyghur community and other Muslim-majority populations.

The text detailed a string of rights violations including torture, forced labour and arbitrary detention. It brought the UN seal to many of the allegations long made by activist groups, Western nations and the Uyghur community in exile.

It said China may have carried out "crimes against humanity" but stopped short of calling Beijing's treatment of Uyghurs "genocide" -- a term used since January 2021 by the United States and since embraced by parliaments in a number of other Western nations.

China has vehemently rejected such charges and criticised Bachelet's report, accusing the UN of becoming a "thug and accomplice of the US and the West".

- 'Remarkably obscure' -

Rights groups have been calling for the next UN rights chief to be courageous enough to take on even the most powerful countries and denounce violations.

"The stakes have never been higher," ISHR programme director Sarah Brooks said in the statement.

The organisation and others have been heavily critical of the opaque nature of the appointment process.

Diplomatic sources in Geneva, where the UN rights office is based, also say that there has until now been little insight.

"It's been a remarkably obscure process," a Western diplomat said.

ISHR director Phil Lynch warned that this lack of transparency and consultation could come at a price.

"The secretary general missed a key opportunity to build the legitimacy and authority of the next high commissioner," he said.

He added though that his organisation and others would "seek to work closely and collaboratively with the next high commissioner to protect human rights and to pursue accountability for perpetrators and justice for victims".