The Federal Emergency Management Agency has announced more than $600m (£446m) in funding for states and local entities to detain undocumented migrants while they await transfer to federal facilities.
The new grant comes as the Trump administration seeks to carry out mass deportations and redefine the disaster relief agency's mission and structure.
Fema says the programme will relieve overcrowding at short-term holding facilities and increase detention capacity in local and state facilities.
The agency had previously administered a shelter and services programme that helped states and cities support non-citizen migrants released by the Department of Homeland Security, its parent agency.
That programme was terminated, however, and the new grant for detentions appeared to be a new iteration of those funds, William Turner, Connecticut's state emergency management director, told the BBC.
