Michelle Bachelet has long sought access to investigate an issue that has soured relations between China and the US, bringing genocide accusations and a diplomatic boycott of the upcoming Winter Games.
China has denounced the claims as an international smear campaign.
Bachelet's office in Geneva said conversations were underway for a possible trip to the area in northwest China in the first half of the year.
The South China Morning Post reported that a visit had been agreed for after the February 4-20 Olympics
"The parameters of that visit are still very much under discussion," Bachelet's spokesman Rupert Colville told a UN briefing, adding that she would need access to civil society actors and high-level engagement from the government.
China has held some visits for journalists and diplomats in recent years, albeit in tightly-controlled conditions.
Rights groups accuse China of widescale abuses against Uighurs and other minority groups, including torture, forced labour and detention of one million people in internment camps
China calls them re-education and training facilities, denies abuses and says it is combatting religious extremism.
Citing unidentified sources, the SCMP said approval for Bachelet's visit was granted on condition it be "friendly" and not framed as an investigation, with no ensuing report.
Colville said the proposed trip was separate from a pending UN report on Xinjiang.
"I can assure you they (our team) will be fending off any untoward approaches," he added.
A Chinese foreign ministry spokesman, Zhao Lijian, said Bachelet had been invited to visit a long time ago for the purpose of exchange and co-operation and added that China opposed any "political manipulation" of a trip.
With the UN Human Rights Council's five-week session set to start on February 28, activists and diplomats say the window is closing for Bachelet to publish the report.
It is thought to be based so far on research and interviews with alleged victims and witnesses inside and outside of both Xinjiang and China.
US lawmakers had wanted it released before the Olympics and activists are frustrated at the delay.
"No one, especially the world's leading human rights diplomat, should be fooled by the Chinese government's efforts to distract attention away from its crimes against humanity targeting Uighurs and other Turkic communities," Sophie Richardson, China director of New York-based Human Rights Watch, said last week.
