UN Secretary-General António Guterres will nominate Austrian Volker Turk as the next High Commissioner for Human Rights, Reuters reports.

Turk, who now serves as UN Under-Secretary-General for Policy, will succeed Michelle Bachelet of Chile, whose term expired on August 31. The appointment must be approved by the UN General Assembly in New York.

The 193-member U.N. General Assembly is likely to approve Turk's appointment later Thursday, diplomats said.

Other candidates for the post included professional diplomat Federico Villegas of Argentina and Adama Dieng of Senegal, who previously advised Guterres on genocide prevention.

Phil Lynch, executive director of the International Service for Human Rights, said there was a lack of transparency and consultation with independent civil society in Turk's selection.

The secretary-general missed a key opportunity to bolster the legitimacy and credibility of the next high commissioner, he said.

Guterres normally consults with the permanent members of the UN Security Council - China, France, Russia, UK and the United States - before selecting a high commissioner. It is not known whether this was done in the case of Turki.