A US Navy veteran is returning home after being freed from detention in Iran.
Michael White was sentenced to prison last year on unspecified charges, but was released temporarily on medical grounds to the Swiss embassy in March.
He was arrested in 2018 after travelling to meet his girlfriend in the city of Mashhad.
The news comes days after an Iranian scientist detained in the US was deported.
Sirous Asgari, a materials science professor from Tehran, had been charged in 2016 with trying to trade secret research from an American university, but was acquitted in November.
The twin releases appear to be a rare example of co-operation between Iran and the US – although Washington has denied so far that it was a straight prisoner swap.
US President Donald Trump confirmed Mr White’s release on Thursday and said the Swiss plane he was travelling on had left Iranian airspace.
“I will never stop working to secure the release of all Americans held hostage overseas,” he said.
“For the past 683 days my son, Michael, has been held hostage in Iran by the IRGC and I have been living a nightmare,” Mr White’s mother said in a statement.
“I am blessed to announce that the nightmare is over, and my son is safely on his way home.”
Mr White was one of at least six US citizens either imprisoned in Iran or out on bail.
He was granted medical furlough to the Swiss embassy in March amid the release of large numbers of prisoners due to the spread of coronavirus in Iran.
His family said he had visited the country a number of times before he was detained.
In December, the US and Iran conducted a prisoner swap in a rare sign of co-operation. Chinese-American researcher Xiyue Wang and Iranian scientist Massoud Soleimani were freed.
Relations between the two countries have been increasingly hostile since the US abandoned the Iran nuclear deal in 2018.
But tensions escalated further this year when the US assassinated top Iranian commander Gen Qasem Soleimani in a drone strike in Iraq in January. Iran retaliated by launching ballistic missiles at Iraqi military bases hosting US forces.