The United States led more than 30 countries on Tuesday in condemning what it called China’s “horrific campaign of repression” against Muslims in the western region of Xinjiang at an event on the sidelines of the annual U.N. General Assembly that was denounced by China.

In highlighting abuses against ethnic Uighurs and other Muslims in China, Assistant Secretary of State John Sullivan said the United Nations and its member states had “a singular responsibility to speak up when survivor after survivor recounts the horrors of state repression.”

Sullivan said it was incumbent on U.N. member states to ensure the world body was able to closely monitor human rights abuses by China and added that it must seek “immediate, unhindered, and unmonitored” access to Xinjiang for the U.N. High Commissioner for Human Rights (UNHCR).

Sullivan said Tuesday’s event was co-sponsored by Canada, Germany, the Netherlands and Britain, and was joined by more than 30 U.N. states, representatives of the European Union and more than 20 nongovernmental organizations, as well as Uighur victims.

“We invite others to join the international effort to demand and compel an immediate end to China’s horrific campaign of repression,” he said. “History will judge the international community for how we respond to this attack on human rights and fundamental freedoms.”

Paola Pampaloni, deputy managing director for Asia of the European External Action Service, said the EU was “alarmed” by the situation and also urged “meaningful” access to Xinjiang.

“We are concerned about … information about mistreatment and torture,” she said. “China is always inviting us to the camps under their conditions, we are in negotiations right now for terms and conditions for free access.”

Tuesday’s event focusing on Xinjiang came a day after U.S. President Donald Trump called for an end to religious persecution at another gathering on the sidelines of the gathering of world leaders, comments he reiterated in his speech to the assembly on Tuesday.

Trump, who has been cautious about upsetting China on human rights issues while making a major trade deal with Beijing an overarching priority, did not mention the Uighur situation specifically, but said religious freedom was under growing threat around the world.

“Americans will never .. tire in our effort to promote freedom of worship and religion. We want and support religious liberty for all.” he told the assembly on Tuesday.

A spokesperson for the Chinese delegation to the high-level meeting of the U.N. General Assembly accused Washington of violating the U.N. Charter by criticizing China at Monday’s religious freedom meeting and Tuesday’s event.

FILE – A Chinese police officer takes his position by the road near what is officially called a vocational education center in Yining in Xinjiang Uighur Autonomous Region, China, Sept. 4, 2018.

The United Nations says at least 1 million ethnic Uighurs and other Muslims have been detained in what China describes as “vocational training centers” to stamp out extremism and give people new skills.

Sullivan said the United States had received “credible reports of deaths, forced labor, torture, and other cruel, inhumane, or degrading treatment” in the camps.

He said there were also many reports that the Chinese government forces detainees to renounce their ethnic identities as well as their culture and religion.

Though U.S. officials have ramped up criticism of China’s measures in Xinjiang, it has refrained from responding with sanctions over the issue, amid on-again, off-again talks to resolve a bitter, costly trade war.

At the same time, it has criticized other countries, including some Muslim states, for not doing enough or for backing China’s approach in Xinjiang.

Rishat Abbas, the brother of Uighur physician Gulshan Abbas, who was abducted from her home in Urumchi in September 2018, told Tuesday’s event that “millions of Uighurs are becoming collateral damage to international trade policies, enabling China to continue to threaten our freedoms around the world, enable it to continue its police state.” 

U.N. human rights chief Michelle Bachelet has repeatedly pushed China to grant the United Nations access to investigate reports of disappearances and arbitrary detentions, particularly of Muslims in Xinjiang.

China’s envoy in Geneva said in June that he hoped Bachelet would visit China, including Xinjiang. Bachelet’s office said in June that it was discussing “full access” with China.