Antonio Guterres says he has repeatedly spoken to China about the country’s detention of more than a million Muslims in the Xinjiang region.

:: UN Secretary-General Antonio Guterres has strongly rejected claims by five human rights groups that he hasn’t condemned the Chinese government’s detention of more than a million Muslims in the Xinjiang region, saying he has spoken out forcefully.

“I don’t think anyone has been more persistent and more clear in talking to the Chinese authorities in relation to this issue than myself,” he told reporters Wednesday. “It is absolutely not true that I’ve only done discreet diplomacy.”

On the contrary, Guterres said that during his visit to Beijing in April, he “not only did raise the issue,” but he “made it public.”

The five rights groups said in a letter to the secretary-general circulated Tuesday that he would make an important contribution to addressing “one of the most pressing human rights issues of our time” by speaking out against China’s internment of the Uighurs and members of other predominantly Muslim ethnic groups and calling for the immediate closure of detention camps for them.

The letter was signed by Human Rights Watch, Amnesty International, the International Commission of Jurists, the International Federation for Human Rights, and the World Uyghur Conference.

Guterres said he told the Chinese “that it is very important to act in a way that each community feels that their identity is respected and that they belong, at the same time, to the society as a whole.”

“There couldn’t be a more clear message,” he said. “So, if there is an area where I believe I’ve been doing publicly much more than many other leaders around the world (it) is this.”

Guterres said he will continue acting to guarantee that “all human rights in all circumstances are fully respected in that situation.”

Does that mean detention centers should be closed? “It will mean to do everything that is necessary for human rights to be respected,” Guterres replied.

Criticism has grown over China’s internment of the Uighurs and other Muslims, and Guterres has been criticized previously by human rights groups and some governments for his behind-the-scenes approach and failure to address their plight publicly.

China’s government insists the detention sites are “vocational” centers aimed at training and skills development. It has sharply criticized 22 Western countries that called for an end to mass arbitrary detentions and other abuses of Uighurs and other Muslims in the Xinjiang region.

In a report earlier this year to counter criticism of internment camps and other oppressive security in the traditionally Islamic region, China said it had arrested nearly 13,000 people it described as “terrorists” and had broken up hundreds of “terrorist gangs” in Xinjiang since 2014.