The last British resident being held at the Guantanamo Bay military prison will be released and returned to his home country.
Shaker Aamer, 46, who has been at the Cuban prison since 2002, has never been charged or been on trial.
British Prime Minister David Cameron, members of Parliament and various British celebrities, including musicians Roger Waters, Peter Gabriel and Sting, had repeatedly urged the Obama administration to transfer Aamer.
Aamer was detained in Afghanistan in 2001. U.S. authorities alleged he had led a unit of Taliban fighters and had met former al-Qaida leader Osama bin Laden. But Aamer maintained he was in Afghanistan with his family doing charity work.
He was cleared for release from Guantanamo in 2007 but remained in custody for another eight years.
His British attorney, Clive Stafford Smith, said the American decision was good news, though many years too late. Once he arrives in Britain, Aamer is likely to be subject to some oversight by the authorities, as part of the deal for his release.
Aamer's daughter, Johina, who last saw her father when she was only 4 years old, wrote on Twitter: "Thank you everyone for all the support. The news hasn't hit yet. We can't believe we might finally see our Dad after 14 years."
The announcement came as President Barack Obama struggles to honor a six-year-old pledge to close the facility before leaving the White House in 2017.
At its peak, Guantanamo housed 700 prisoners accused by the U.S. of involvement in terrorism. There are 114 detainees remaining at Guantanamo, and of those, 53, like Aamer, have been recommended for transfer if security conditions can be met.