While critics argue the UN is costly and needs reform, officials warned that withdrawing would allow China to expand its influence and put the U.S. at a strategic disadvantage.

The United Nations is bloated, costly, badly in need of reform, and too often works against US interests, but pulling out of the international organisation would see China expand its influence and leave Washington at a major disadvantage, according to testimony before a House oversight committee on Wednesday. The hearing came as the administration of US President Donald Trump has imposed an “America first” overhaul of international funding, leaving the UN, over the past 18 months, at what...