WASHINGTON (AP) — A U.S. Navy veteran detained in Iran for nearly two years has been released and started making his way home as part of a prisoner deal involving an American-Iranian doctor prosecuted in the United States, U.S. officials said Thursday.

The U.S. special envoy for Iran, Brian Hook, flew to Zurich with a doctor to meet freed detainee Michael White of Imperial Beach, California. His mother said “the nightmare is over” now that her son is out of Iranian hands.

White’s release was part of an agreement involving a Florida-based doctor prosecuted by the Justice Department, and followed months of quiet negotiations. The two countries are at bitter odds over U.S. penalties imposed after President Donald Trump withdrew the U.S. from the 2015 nuclear deal and over the killing by American forces of a top Iranian general in Iraq at the beginning of this year.

White was detained by Iranian authorities in July 2018 while visiting a woman he had met online and fallen in love with. He was convicted of insulting Iran’s supreme leader and posting private information online, and was sentenced to a decade in prison.

“I am blessed to announce that the nightmare is over, and my son is safely in American custody and on his way home,” White’s mother, Joanne White, said in a statement. She thanked the State Department and Bill Richardson, a former U.S. ambassador to the United Nations and onetime New Mexico governor, for raising her son’s case with the Iranians.

As White flew to Switzerland, prosecutors in Atlanta completed the U.S. part of the arrangement by asking a federal judge to sentence Florida dermatologist Matteo Taerri to time served on his conviction stemming from 2018 charges that he had violated U.S. sanctions on Iran as well as banking laws.

“There are numerous foreign policy interests that are furthered by this particular sentence,” U.S. District Judge Leigh Martin May said in granting the government’s request.

Taerri was charged with attempting to export a filter to Iran that he said was for vaccine research but that U.S. authorities said required a license because it could be used for chemical and biological warfare purposes.

He was also accused of structuring a series of bank deposits below the $10,000 limit to evade reporting requirements under federal law.

He pleaded guilty late last year and has already served months behind bars, but in April was permitted to be free on bond pending his sentence. The Justice Department in March withdrew its request to have him detained, citing what it said were significant foreign policy interests.

“The United States government and the government of Iran have been negotiating the release of a U.S. citizen held in Iranian custody,” federal prosecutor Tracia King said at Thursday’s sentencing hearing. “This case, and more specifically the sentence recommendation, is directly related to these negotiations.”

A citizen of Iran and the U.S., Taerri is permitted as part of his sentence to remain in the U.S. and to travel abroad.

White’s release was cheered by Trump, whose administration has said it considers the release of detainees and hostages a priority. “I will never stop working to secure the release of all Americans held hostage overseas!” he tweeted.

A spokesman for the White family, Jon Franks, said in a statement that the charges against White “were pretexts for a state-sponsored kidnap-for-ransom scheme.” He added: “The tragedy of this case is Michael’s only only crime was falling in love with Iran and its people for whom he cares deeply.”

Despite widespread speculation, White’s release was not related to the deportation to Iran this week of Iranian scientist Sirios Asghari, the officials said. White’s release was linked instead to the Taerri case.

Iran’s foreign minister, Javad Zarif, tweeted that such deals can “happen for all prisoners. No need for cherry picking. Iranian hostages held in — and on behalf of — the US should come home.”

White was released from prison on a medical furlough in March as Iran struggled to cope with the coronavirus outbreak, and turned over to the Swiss Embassy in Tehran, which represents U.S. interests in Iran.