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

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

Trump's first U.N. 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.