More than 14 years have passed since the Guantanamo Bay detention facility was established, and despite promises to close the controversial prison, the complex remains operational.

Initially meant to house "the worst of the worst," the prison has been known to hold prisoners without formal charges. Three detainees who were never charged were transferred on Saturday from the facility to Italy and Serbia.

Umar Abdulayev, 37, of Tajikistan, has been held at Guantanamo since 2002. He was released to Serbia after being held for 14 years without charges. The same is true for Yemeni national Mansur Ahmad Saad al-Dayfi, who also was released to Serbia. Yemeni national Fayiz Ahmed Yahia Suleiman was released to Italy after being held in Guantanamo since 2002, also without charges. He was first recommended for transfer in 2010.

The Guantanamo Bay detention facility was established in 2002 under the President George W. Bush administration and continues to operate under President Barack Obama. However, in 2009, Obama used his first executive order to call for its closure within a year. In spite of the order, logistical, legal and political issues slowed the process in place to release cleared prisoners and try those who have been charged with war crimes.

Of the 76 detainees remaining at Guantanamo -- excluding the three who just left -- 27 have been approved for transfer. Thirty-six have not been cleared for release and have also not been charged with any crimes. The remaining 10 detainees have been charged with crimes. Their cases are being handled through ongoing military commissions hearings.

Of the prisoners who have been charged, five of them are accused of participating in the Sept. 11, 2001, attacks. Pre-trial hearings are scheduled weeks or months apart to give the judge and lawyers on both sides time to gather pertinent information and to accommodate other hearings at the Guantanamo facility.

In the waning months of the Obama administration, there is a sense of urgency regarding whether the president will honor his promise to close the facility. But the complicated tasks of holding hearings, conducting trials and finding host countries that are already cleared to take transfers could take years, making it unlikely that the facility will close during Obama's term.

Since 2009, 30 countries have offered to host and resettle Guantanamo detainees. Combined, they've taken in more than 100 detainees.

What happens next with the Guantanamo facility will be left to the next president.

Presumptive Democratic presidential nominee Hillary Clinton has repeated her backing of Obama's proposal to close the detention facility as quickly as possible. Likely Republican presidential nominee Donald Trump has taken a different stance on the facility, vowing to keep it open and "load it up with some bad dudes."