The U.S. Defense Department announced Saturday it sent nine Yemeni prisoners from the Guantanamo Bay detention facility to Saudi Arabia, including one who conducted a longterm hunger strike.

“The United States is grateful to the government of the Kingdom of Saudi Arabia for its humanitarian gesture and willingness to support ongoing U.S. efforts to close the Guantanamo Bay detention facility,” the Pentagon said in announcing the transfer.

The release means 80 prisoners are left at the prison on the U.S. Naval Base at Guantanamo Bay, Cuba. Twenty-six others are expected to be sent to another country by the end of the summer, the Associated Press reported. Most of the detainees have been held without trial, drawing condemnation from the international community.

The release is part of a plan by the Obama administration to close the facility, a promise President Barack Obama made during his first campaign for the White House but has yet to fulfill, largely in the face of congressional opposition. Obama wants the several dozen remaining prisoners to be moved to a maximum-security prison in the United States.

Hunger striker Tariq Ba Odah, 37, of Yemen was among those released. His weight dropped to a dangerously low 74 pounds at one point, prompting the military to stop him from starving to death by force-feeding him liquid nutrients.

Odah and seven others had been cleared for release since January 2009. The ninth, Mashur Abdullah Muqbil Ahmed al-Sabri, was cleared last year, the AP said.

The release represents the largest since Obama rolled out a plan in February to close the detention center before he leaves office next January, Reuters reported. The announcement comes as Obama prepares to attend a summit with Gulf Arab allies in Saudi Arabia Wednesday.

CNN reported the other prisoners were identified as Ahmed Umar Abdullah Al-Hikimi, Abdul Rahman Mohammed Saleh Nasir, Ali Yahya Mahdi Al-Raimi, Muhammed Abdullah Muhammed Al-Hamiri, Ahmed Yaslam Said Kuman, Abd al Rahman Al-Qyati and Mansour Muhammed Ali Al-Qatta.