Osama bin Laden's former cook on Wednesday pleaded guilty at a US military trial in Guantanamo Bay to providing support to terrorism and conspiracy, the first conviction for the Obama administration at the controversial court.

Ibrahim Ahmed Mahmoud al-Qosi, 50, who has been held at the US-run prison in Guantanamo since 2002, admitted that he gave logistical support to Al-Qaeda with full knowledge that the group engaged in acts of terrorism, the Pentagon said in a statement.

"His sentence will be determined at a hearing in August," Major Tanya Bradsher told AFP in an email from the US naval base in Guantanamo Bay, Cuba.

Qosi, from Sudan, admitted to the charges in a plea deal but had faced a possible life sentence if convicted in a trial.

Prosecutors and defense lawyers did not divulge details of the agreement, including possible limits on his prison sentence.

Under oath, Qosi acknowledged that he had backed Al-Qaeda since 1996 and had followed bin Laden to Afghanistan, where he worked as a cook at a compound in Jalalabad and also served as a bookkeeper and logistics chief.

President Barack Obama has promised to close the prison in Guantanamo, set up after the September 11, 2001 attacks to hold terror suspects, but has had to delay plans amid opposition from Congress to moving some detainees to US soil.

Qosi was tried under revised rules introduced by the Obama administration to address criticisms of the commission system.

But human rights groups said the case was an example of how the commission is fundamentally flawed and plagued by delays compared to federal criminal courts.

"This is not a victory for the military commission system," Daphne Eviatar of Human Rights First said in a statement.

"In fact Mr. al-Qosi's case is a textbook example of the inability of the military commission system -- now in its third incarnation -- to achieve swift justice.

The case has dragged on for more than six years without a trial," she said.

(Source: AFP)