(AP) -- A federal official says the Obama administration wants to buy a nearly vacant prison in northwestern Illinois even if Guantanamo Bay detainees aren't transferred there.

The Department of Justice official spelled out the administration's plan in a letter released Thursday by Republican Congressman Don Manzullo's office.

The government wants to buy the Thomson Correctional Center to help relieve federal prison overcrowding and use it as a home for some detainees. Obama has promised to close the U.S. detention facility in Cuba.

Manzullo spokesman Rich Carter says the congressman supports using the prison to house federal inmates but not detainees.

Supporters say selling the prison to the federal government could spur economic growth desperately needed in the farming community where the prison is located about 150 miles west of Chicago.