In a rare admonishment of the United States, Spain's foreign minister said Tuesday the indefinite detention of terrorism suspects at the U.S. Navy base in Guantanamo Bay was a "major error."

Foreign Minister Ana Palacio (search) told Spanish television channel Telecinco she hoped the U.S. Supreme Court would "open a path" that would remove the prisoners from "legal limbo." Palacio, along with the governing Popular Party (search), is known for her consistent support of the Bush administration and its war on terror.

The minister spoke one day after the U.S. Supreme Court agreed to hear an appeal asking whether foreigners held at Guantanamo Bay (search) in Cuba may contest their captivity in American courts.

The case concerns more than 650 prisoners held essentially incommunicado at Guantanamo Bay following the Sept. 11, 2001, terrorist attacks. The Bush administration maintains that because the men were picked up overseas on suspicion of terrorism and are being held on foreign land, they may be detained indefinitely without charges or trial.

Palacio said the Spanish government had been "very clear" on its position on the Guantanamo Bay detainees.

She said authorities were in contact with a Spanish national held at Guantanamo Bay for suspected ties with Al Qaeda, and were conducting "a critical dialogue" with the American authorities.

Palacio told Telecinco that a U.S. delegation would travel to Madrid in the coming days to meet with Spanish officials "to see what solution can be found" in the case of the Spaniard because "this situation cannot continue."