Millions of international soccer fans traveling to the United States to attend the FIFA World Cup this summer could face major problems getting into the country in over half of the host cities.

Homeland Security Secretary Markwayne Mullin confirmed on Tuesday that his agency was moving forward with plans to shut down customs operations at airports in sanctuary cities, or places that do not allow federal law enforcement from U.S. Immigration and Customs Enforcement to take custody of illegal immigrants in county jails and state prisons.