Iran has granted a medical furlough to a U.S. Navy veteran who has been imprisoned in Iran for more than a year, Secretary of State Mike Pompeo announced Thursday. Michael White of Imperial Beach, California, is now in the custody of the Swiss Embassy and must remain in Iran as a condition of his furlough, which was granted as Iran works to curb the spread of coronavirus.

The U.S. government will seek his full release, Pompeo said, and he called on Iran to free other Americans who remain jailed there.

A spokesman for the White family said the family was grateful to the Iranian government for an "interim humanitarian step."

Michael White, a Navy veteran imprisoned in Iran, was freed Monday for medical reasons on condition that he stay in the country, Secretary of State Mike Pompeo said. Michael White's family

"We continue to urge them to release Michael unconditionally so that he can return to the United States to receive the advanced medical care he needs," spokesman Jon Franks said in a statement to CBS News.

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White, who had been imprisoned since July 2018, was visiting a girlfriend in Iran when he was detained. White was convicted of insulting Iran's supreme leader and posting private information. He was sentenced to 10 years in prison, though the State Department said he was serving a 13-year sentence.

Iran has granted temporary release to tens of thousands of prisoners in recent weeks to try to contain a virus that officials fear could kill millions in the country.

In September, White's mother, Joanne, told CBS News this week that her son's recurring health problems are deteriorating, and she's "really worried he'll die over there."

In an interview with The Associated Press this month, White's mother called on Iran to immediate release her son, saying she was especially concerned for his well-being because he has been battling cancer.

Iran this week issued its most dire warning about the outbreak, saying millions could die in the Islamic Republic if people keep traveling and ignore health guidance. Roughly 9 out of 10 of the 18,000-plus confirmed cases of the virus in the Middle East come from Iran.

Before the announcement, Iran had released 85,000 prisoners on temporary leave, including Nazanin Zaghari-Ratcliffe, an Iranian-British dual national long held on internationally criticized charges.