An Iranian scientist detained in the United States was flown back to Iran on Tuesday, a possible precursor to a prisoner exchange between the countries despite their intensifying hostility since President Trump took office more than three years ago.
Iran’s foreign minister, Mohammad Javad Zarif, said the scientist, Sirous Asgari, was en route home, which Mr. Zarif described as “great news” in an announcement on his Instagram account. A spokesman for Iran’s Foreign Ministry, Seyed Abbas Mousavi, told Iranian news media that Mr. Asgari would arrive in Tehran on Wednesday morning.
The release of Mr. Asgari has long been anticipated by Iranian officials. While they denied his release was part of any prisoner swap, there have been indications that it would be seen as a positive gesture by the United States that could help lead to the release of at least one American held in Iran. At least four are known to be in custody.
Mr. Asgari was acquitted last November in federal court on charges of stealing trade secrets in violation of sanctions while on a sabbatical visit at an American university in Ohio. ICE agents detained him for deportation after his case had been dismissed.
He was infected with the coronavirus while held at an ICE detention center in Louisiana, delaying his return home. American officials tried to send him back to Iran in March, flying him around the United States nine times in an attempt to put him on a flight with connections to Iran, but the pandemic lockdowns canceled almost all international air travel.
Speculation has persisted that an American Navy veteran, Michael R. White, 48, who has been held in Iran for nearly two years, could soon be permitted to return to the United States once Mr. Asgari was back in Iran. Like Mr. Asgari, Mr. White was infected with the coronavirus while in custody.
Mr. White, a cancer survivor, had been visiting an Iranian woman he met on the internet when he was arrested in July 2018 and later sentenced to a 10-year prison term on murky charges.
He was furloughed from prison a few months ago when the coronavirus contagion became a crisis in Iran. Swiss diplomats, who act on behalf of the United States in Iran, have been looking after his case.
It remained unclear late Tuesday whether there had been any change in Mr. White’s status in Iran.
Jonathan Franks, a spokesman for Mr. White’s family, said he had no news of his imminent release or any indication that Mr. Asgari’s release would play a role.
In Washington, a senior State Department official said nothing had changed concerning Mr. White and that since his furlough from prison he had been living under “whatever arrangements the regime worked out with the Swiss.”
The prisoner issue has long been a volatile point of contention in the estranged relations between Iran and the United States. Each has accused the other of holding its citizens for political reasons.
In December, Iran freed Xiyue Wang, a Princeton graduate student charged with spying, in a swap for an Iranian scientist who had been convicted in the United States on charges of violating American trade sanctions.
Rick Gladstone and Lara Jakes contributed reporting.