Four Yemeni inmates released from the US Guantanamo Bay military prison in Cuba have landed in Saudi Arabia.
The releases signal a final push by President Barack Obama to reduce inmate numbers before he leaves office.
An AFP journalist said he saw the four men welcomed by tearful family members at Riyadh airport, reportedly via a terminal usually reserved for royals.
President-elect Donald Trump had on Tuesday called for all further releases to stop.
Up to another 15 prisoners are expected to be transferred before Mr Obama hands power to Mr Trump on 20 January.
They will be sent to at least four countries, including Italy, Oman and the United Arab Emirates.
The prisoners have all undergone lengthy reviews and parole-style hearings, and were deemed safe for repatriation or resettlement overseas.
When he took office eight years ago, Mr Obama pledged to close the controversial Guantanamo Bay facility entirely.
He argued that it compromised American values, after it became associated with lengthy detention without trial, force-feeding, sleep deprivation, stress positions and beatings.
The US Congress blocked his closure plans, but with regular transfers only about 40 prisoners will remain if the last releases go ahead.
During his presidential election campaign, Mr Trump had vowed to keep the prison running and “load it up with some bad dudes”.
In a tweet on Tuesday, the Republican declared: “There should be no further releases from Gitmo. These are extremely dangerous people and should not be allowed back on the battlefield.”
Mr Obama inherited 242 detainees at Guantanamo Bay when he succeeded George W Bush as president.
Of the 59 prisoners who remained before the latest transfer, 10 are facing charges in military tribunals, including the alleged plotters of the 11 September attacks. Around two dozen have not been charged but are deemed too dangerous to release.
Last April, nine Yemeni inmates were transferred from Guantanamo Bay to Saudi Arabia – the first time the kingdom had accepted prisoners from the facility.
The ongoing civil war in Yemen meant they could not be sent back to their native country.
The deal followed years of negotiations with the Saudi government. It was agreed that the former inmates would participate in a Saudi rehabilitation and de-radicalisation programme.