US Customs and Border Protection turned back Omar Artan at Miami on 7 June despite his valid visa. Artan was one of 52 World Cup referees appointed by football's governing body. Somalia is on the Trump travel ban list; Artan would have been the first Somali to officiate a World Cup match.
The host-agreement places immigration sovereignty with the US government, not the governing body. No replacement was named by 9 June.
