The tour by Michelle Bachelet marks the first by the UN's top rights official in nearly two decades and comes as Beijing stands accused of the widespread abuse of Muslims in the western autonomous region of Xinjiang.
According to the New York-based Human Rights Watch (HRW), the Chinese leadership is responsible for "widespread and systematic policies of mass detention, torture and cultural persecution" in Xinjiang.
According to HRW's China director, Sophie Richardson, “Beijing has said it is providing ‘vocational training’ and ‘deradicalisation,’ but that rhetoric can’t obscure a grim reality of crimes against humanity.”
The French, Dutch and Canadian parliaments have all presented resolutions branding Beijing's policy in Xinjiang as "genocide."
China vociferously denies the accusations, calling them "the lie of the century".
Bachelet conducted virtual meetings with the heads of around 70 diplomatic missions in China on Monday, according to sources in Beijing, who said she gave assurances about her access to detention centres and rights defenders.
Later in the week, she is due to travel to the Xinjiang cities of Urumqi and Kashgar as well as the southern city of Guangzhou.
Welcoming the visit, Beijing's foreign ministry spokesman Wang Wenbin said Bachelet will "have extensive exchanges with people from various sectors," without giving more details.
UN officials have been locked in negotiations with the Chinese government since 2018 in a bid to secure "unfettered, meaningful access" to Xinjiang.
