The US Supreme Court has agreed to hear the appeal of a US citizen captured in Afghanistan in 2001 who is being held without charge in a US military jail.
Hamdi was originally among those taken to Guantanamo Bay
Yaser Esam Hamdi, 22, is challenging the decision to label him "an enemy combatant", thus making him ineligible for normal legal protection.
The court is expected to hear his case in April and rule on it by July.
It could become a test case for the Bush administration's handling of the war against terrorism, observers say.
Mr Hamdi, who is being held at a naval prison in Charleston, South Carolina, disputes the US Government's right to hold him indefinitely.
The Bush administration has classified him as a danger to the US, although in December the Pentagon decided to allow him access to a lawyer.
Jose Padilla - another "enemy combatant" challenging his status
Mr Hamdi was captured among Taleban fighters during the US-led operation in Afghanistan in 2001.
"Hamdi is a classic battlefield detainee - captured in Afghanistan, an area of active combat, with an enemy unit," Solicitor-General Theodore Olson has said.
He was first taken to the detention camp in Guantanamo Bay in Cuba, but transferred to the naval jail when it was determined that he was a US citizen.
Although he was born in Baton Rouge, Louisiana, Mr Hamdi moved to his parents' home country of Saudi Arabia as a child.
Correspondents say the Supreme Court's decision is another legal setback for the US Government.
Last month, a federal appeals court in New York ruled that Jose Padilla - a US citizen accused of involvement in a "dirty bomb" plot - could not be held indefinitely.
Mr Padilla, 33, also declared an enemy combatant, has been at the same naval facility in South Carolina as Mr Hamdi since June 2002.
The New York court gave the government 30 days to release him.
The Justice Department has said it is planning to appeal against that decision.
The Supreme Court is already investigating whether the foreign detainees in Guantanamo are entitled to have access to lawyers and the US courts.
It is expected to make a ruling sometime in the first half of this year.
Other pending court cases connected with US action against terror suspects include:
- Detainees at the US detention camp in Guantanamo Bay who are seeking the right to challenge their treatment in American courts
- Public interest groups which are trying to force the US Government to disclose information about more than 700 immigrants arrested in the months after the 11 September attacks
- An Algerian waiter, Mohammed Kamel Bellahouel, who has challenged his detention in Florida and the secrecy surrounding the conduct of his case.