China's ambassador to the United Nations in Geneva said on Friday that Beijing would not cooperate with the U.N. human rights office following the release of a long-awaited report on alleged human rights abuses in the far western region of Xinjiang.

The report, which China had sought to bury, stipulates that "serious human rights violations have been committed" in China and said the detention of Uyghurs and other Muslims in Xinjiang may constitute crimes against humanity.

"The office closed the door of cooperation by releasing the so-called assessment," Ambassador Chen Xu told reporters, describing the report released on Aug. 31 as "illegal and invalid". China vigorously denies any abuses in Xinjiang.

The report was released minutes before outgoing High Commissioner Michelle Bachelet ended her four-year term and followed her visit to the country in May.

It recommends prompt steps to release all those detained in training centres, prisons or detention facilities. It also envisages continued engagement between the U.N. rights office and Beijing including future meetings and follow-up visits as agreed between Bachelet and Beijing at the end of her visit.

"Now the whole set of ideas is shelved because of the release of the report," Chen told reporters. "You cannot... hurt us while in the meantime enjoy cooperation with us."

The China report is expected to be discussed during a meeting of the Human Rights Council which opens next week. Chen said he would "firmly oppose" any measures against China in that session.

Previously, Bachelet had been accused by some rights activists of being too soft on China although the hard-hitting report helped redeem her credibility in the eyes of some.

Chen said he felt the apparent changes in Bachelet's stance indicated she did not support the report's conclusions.

"If I read her mind correctly, I don't think she's on board with the report and that's why it was released in the last minute," he said.

The Office of the High Commissioner for Human Rights is currently being run by a deputy pending the arrival in Geneva of Austria's Volker Turk who was appointed on Thursday.

An OHCHR spokesperson declined to provide an immediate comment on the Chinese ambassador's remarks.