Indonesian terror suspect Hambali, now held in Guantanamo Bay, appeared on Thursday before a board evaluating his suitability for release, as the Obama administration continued its push to close the controversial detention facility.

Wearing a white T-shirt and glasses, the man who masterminded the 2002 Bali bombing sat calm and expressionless throughout the portion of the Periodic Review Board hearing that was beamed to the Pentagon for media and observers from non-governmental organisations.

The 52-year-old, whose real name is Riduan Isamuddin, looked healthy and was sporting a full beard.

He has rarely been seen by members of the public since his capture in Thailand in 2003. However, no photography or recordings were allowed while the case was being heard.

Hambali's Pentagon-appointed representative read out a brief statement making the case for his release, saying that the detainee has been cooperative and harboured no ill-will towards the United States.

"He believes America has diversity and sharing of power, which is much better than a dictatorship. He states that he wants nothing more than to move on with his life and be peaceful," said Hambali's representative. "He hopes to remarry and have children to raise."

He also added that Hambali taught himself English and Arabic while in detention, and subsequently held Arabic classes for his fellow detainees.

However, the US government's unclassified summary of Hambali argued that the Indonesian would likely be a significant threat if released.

It said Hambali has been heard "promoting violent jihad while leading daily prayers and lectures".

"He most likely would look for ways to reconnect with his Indonesian and Malaysian cohorts or attract a new set of followers if he were transferred from Guantanamo Bay," it said, adding that Hambali's younger brother, Rusman Gunawan, was a member of the Indonesia-based network of the Islamic State in Iraq and Syria (ISIS) group.

It is unclear when the Periodic Review Board will render its decision on Hambali. The gap between hearings and verdicts have varied from a few months to a few years.

The Indonesian government has made it clear it is reluctant to accept his repatriation from the US. In March, Indonesia's Coordinating Minister for Political, Legal and Security Affairs Luhut Pandjaitan told reporters that the US would not deport Hambali to Indonesia even if Guantanamo is shut down.

Hambali, once referred to by the Central Intelligence Agency as South-east Asia's Osama bin Laden, is among the highest-profile detainees to have come before the review board at a time when President Barack Obama appears to be stepping up efforts to shut down Guantanamo Bay.

As the former military leader of Indonesian terrorist group Jemaah Islamiyah, he had ties with Al-Qaeda.

Earlier this week, the Pentagon announced that 15 detainees had been transferred to the United Arab Emirates. It was the largest such transfer under Mr Obama and brings the remaining population of Guantanamo down to 61 from a high of 780.