Officials at the Department of Homeland Security and the Defense Department are racing to set up multiple tent facilities in Guantanamo Bay, Cuba, to house thousands of migrants, but the scattered efforts have prompted questions internally about who’s in charge and what will happen once people arrive on site.

WASHINGTON—The American Civil Liberties Union sued the Trump administration Wednesday for access to migrants transported from the U.S. mainland to Guantanamo Bay Naval Base in Cuba, arguing that the government is denying rights the detainees may have under the Constitution and federal law.