The Trump administration has denied visas to dozens of women scheduled to attend a United Nations women’s conference this month. Campaigners say at least 41 women were denied entry to the U.S. to attend the annual Commission on the Status of Women—most of them from nations blacklisted under Trump’s travel ban. The move is an apparent violation of a 70-year-old treaty which obligates the U.S. to allow entry to people attending the United Nations headquarters in New York City.