The United States is considering how it will confront China during the annual gathering of world leaders at the United Nations next week over its detention of some 1 million Muslims in a remote region, as some diplomats warn that US leadership in global institutions is waning and China’s influence is growing.

“China is taking advantage in the UN of the relative antagonistic, critical attitude of the USA towards the UN itself, and is occupying spaces and projecting influence much more than before,” said a senior European diplomat, who spoke on condition of anonymity.

During the high-level UN gathering next week, Secretary of State Mike Pompeo has said the United States would seek support in calling out China’s detention policy in remote Xinjiang, where the United Nations says at least 1 million ethnic Uighurs and other Muslims have been detained.

While the United States is the largest financial contributor to the UN budget, President Donald Trump has questioned the value of multilateralism as he focuses on an “America First” policy and touts the protection of US sovereignty.

Trump’s first UN envoy, Nikki Haley, stepped down at the end of 2018, and was replaced just last week by Kelly Craft, whose foreign policy experience pales in comparison to that of her veto-wielding Security Council counterparts from Russia, China, France and Britain.

Pompeo in July called China’s treatment of Uighurs the “stain of the century,” saying at an international conference in Washington that China was “home to one of the worst human rights crises of our time.”

A senior US administration official, speaking on condition of anonymity, said the White House was considering whether Trump might mention China’s treatment of the Uighurs and possibly its broader human rights record in his speech to the 193-member UN General Assembly next Tuesday.

The White House said Trump would host a “Global Call to Protect Religious Freedom” at the United Nations on Monday, the day before his address to the General Assembly, and would be introduced by Vice President Mike Pence.