Donald Trump has thanked Iranian authorities for the prisoner swap between Washington and Tehran. "Thank you to Iran on a very fair negotiation", the US president wrote on his Twitter page.
US Secretary of State Mike Pompeo confirmed on Saturday that US citizen Xiyue Wang, who had been detained in Iran on spying charges for three years, was released by Tehran.
He also thanked the Swiss government for facilitating the return of the detainee and Tehran for cooperating on the matter. Switzerland mediated the talks between the countries as it has represented US interests in Tehran since the countries severed diplomatic relations after the 1979 Islamic Revolution in Iran.
Earlier in the day, Iranian Foreign Minister Javad Zarif tweeted that Tehran and Washington were conducting an exchange of Wang, a Chinese-American Princeton scholar, and US-held Iranian scientist Massoud Soleimani.
"There has been absolutely no payments of cash, or lifting of sanctions, or any sort of concessions or ransom ... That may be one of the reasons why it has taken some time", the official stated.
He confirmed that Soleimani was freed, while stressing that it was not a "blind" prisoner exchange case. The official noted that the case could rather be considered as mutual humanitarian measures by the two countries, adding that the US citizen's release was "an extraordinary good outcome to the United States".
Wang was convicted on espionage charges and sentenced to 10 years in prison in Iran in 2017. Soleimani, a stem cell expert, was arrested in 2018 at Chicago airport for allegedly trying to export biological materials to Iran in violation of US sanctions. Both denied the allegations.