0157 GMT January 29, 2020
An Iranian scientist held in the United States and an American researcher detained in Iran have been released, the two sides declared Saturday, in an apparent prisoner swap at a time of heightened tensions.
Tehran announced the release of Iranian scientist Massoud Soleimani from the US shortly before Washington said American researcher Xiyue Wang was returning home.
"Glad that Professor Massoud Soleimani and Mr. Xiyue Wang will be joining their families shortly," Iran's Foreign Minister Mohammad Javad Zarif tweeted.
The exchange was conducted in Zurich, Switzerland.
"Many thanks to all engaged, particularly the Swiss government," which has looked after US interests in Iran in the absence of diplomatic ties, Zarif added.
Zarif later posted pictures of himself on Twitter with Soleimani in front of an Iranian government jet and later with the two talking on board.
Iran’s official news agency IRNA said Soleimani, who had faced a federal trial in Georgia, was "freed moments ago after one year of illegal detention and was handed over to Iranian officials in Switzerland".
It also reported that Wang was released based on “Islamic clemency”.
Soleimani is a professor and senior stem cell researcher at Tehran's Tarbiat Modares University, who left for the United States last year.
Soleimani — who also researches in hematology and regenerative medicine — was arrested by American authorities in October 2018 on charges he had violated trade sanctions by trying to have biological material brought to Iran. He and his lawyers maintained his innocence, saying he seized on a former student plan to travel from the US to Iran in September 2016 as a chance to get recombinant proteins used in his research for a fraction of the price he would pay at home.
In a statement issued in Washington, US President Donald Trump said that "after more than three years of being held prisoner in Iran, Xiyue Wang is returning to the United States".
“We thank our Swiss partners for their assistance in negotiating Mr. Wang’s release with Iran,” Trump said.
US Secretary of State Mike Pompeo said in a tweet that he was “pleased that the Iranian government has been constructive in this matter”.
Wang, a Chinese-born American, was serving 10 years on espionage charges in Iran.
A doctoral candidate in history at Princeton University, he had been researching Iran's Qajar dynasty when he was imprisoned in August 2016.
According to Princeton, he was born in Beijing in 1980, immigrated to the United States in 2001 and became a naturalized US citizen in 2009. His wife and child are Chinese citizens.
Princeton University spokesman Ben Chang said the school was aware of Wang’s release.
Brian Hook, the US special representative for Iran, accompanied the Iranian scientist to Switzerland to make the exchange and will return with Wang, according to a US official. Hook and Wang were en route to Landstuhl hospital at Ramstein Air Base in Germany where Wang will be examined by doctors, the official said. Hook is expected to return to the US from Germany alone, as Wang is expected to be evaluated for several days.
Although Hook was present for the swap, the official said Trump’s National Security Adviser Robert O’Brien played the lead role in the negotiations.
The United States and Iran have not had diplomatic ties since 1980.
Tensions have been high between the two since Trump unilaterally withdrew Washington from Iran’s nuclear deal with world powers in May 2018. Ever since, the US has imposed harsher sanctions on Iranian economy.
Zarif in September said in an interview with NPR that he had pushed for an exchange of Wang for Soleimani.
“I have offered to exchange them, because as foreign minister I cannot go to our court and simply tell them, ‘Release this man,’” Zarif said then. “I can go to the court and tell them, ‘I can exchange this man for an Iranian,’ and then ... have a legal standing in the court.”
However, it remains unclear whether this exchange will have a wider effect on Iran-US relations.
AFP, AP and Reuters contributed to this story.