Guantanamo Bay: 75 US lawmakers call on Biden to 'immediately close' prison
The letter, led by Congressmen David Price and Adam Schiff, and Congresswoman Ilhan Omar, is the latest effort from Congress to pressure the White House into closing the infamous detention facility.
"The continued operation of the prison is a stain on our international reputation and undermines our ability to advocate for human rights and the rule of law," read the letter, sent on Wednesday.
"We recognize that closing the prison will take time, but we believe the time has come with your leadership."
The Biden administration has previously said it planned to close the prison before the end of the president's term in office, however, has not publicly provided a concrete plan or timetable.
White House Secretary Jen Psaki said in February that closing the high security prison "certainly is our goal and our intention", and the National Security Council has also reportedly launched a formal review of the Guantanamo Bay prison.
US Secretary of Defense Lloyd Austin also previously told Congress that the administration would add no new detainees to the facility and seek its closure.
"Even in our darkest moments, we must always uphold core American values, including respect for the rule of law, due process, and human rights," Price said in a statement announcing the letter.
"It is time we work together to finally close the Guantanamo Bay detention facility."
The prison at the US naval base at Guantanamo Bay was established in 2002 and at its height held 780 detainees, but after nearly two decades that number has dwindled to 39 detainees, 10 of whom have been approved for transfer to other countries.
In April, two dozen senators sent a similar letter to Biden, calling the prison a "symbol of lawlessness and human rights abuses".
Transparency in military commission
The letter comes several weeks after the Biden administration transferred its first detainee from the detention centre, a Morrocan man named Abdul Latif Nasser who had been held there for nearly 20 years without charge. Nasser was transferred to his home country.
The release was applauded by rights groups, however, advocates have also called on the US to ensure that transferred detainees are sent to countries under conditions that ensure their safety.
Some detainees who have left the prison, such as former Red Army ballet dancer Ravil Mingazov, have been sent to countries where they have been subject to further imprisonment or strict surveillance.
In addition to calling for the prison's closure, the members of Congress also urged greater transparency in the military commission process, and to post the proceedings online.
Military commissions have been set up to try individuals for "unlawful conduct associated with war", but the Military Commission at Guantanamo is considered to be the biggest such criminal trial in US history.
Established in 2006, the commission has moved along at a notoriously slow pace and defence attorneys for those held at Guantanamo have continuously complained of government overreach.
They say military officials on base have read their mail and installed monitoring devices in attorney-client meeting rooms.
Access to the proceedings is also limited, with the only ways to access them being to either travel to Guantanamo Bay or to watch them at a limited number of US military bases, according to the lawmakers' letter.
"Given the glacial pace of the commission process, we believe that transparency would be beneficial," the letter read.