Michael White, a U.S. Navy veteran, has been sentenced to serve at least 10 years in prison in Iran, an attorney for his family said Saturday. White was detained while visiting his Iranian girlfriend in July 2018 on charges he insulted Iran's supreme leader, Ayatollah Ali Khamenei, and posted a private photograph on social media.

Mark Zaid, the White family's lawyer, told CBS News that White was sentenced to two years in prison on the charge of insulting the supreme leader and 10 years for posting the photo. Zaid said he believes the sentences are to run concurrently.

Zaid told The New York Times the White family was informed of the sentence earlier this week by the State Department, which learned of the sentence from Swiss diplomats representing American interests in Iran. White has been permitted to meet with the Swiss twice since his arrest, Zaid said. The State Department said Saturday it was aware of his detention but declined further comment due to privacy concerns.

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White was tried, convicted and sentenced over the course of two hearings on March 6 and 9, Zaid said. White has 22 days to appeal, but it's unclear "when that clock started ticking," Zaid said.

White's mother, Joanne, spoke to "CBS Evening News" in January to discuss her concerns about her son's health.

Joanne White said she prays every day that her son Michael will be freed from prison in Iran before it's too late. She worried his recurring cancer could come back.

"I knew he wasn't dead. I felt that in my heart. But I didn't think he was OK," she said.

Zaid said Swiss diplomats who met with White indicated he was in good health.

"The Swiss came back with favorable report that he seems to be holding up well. He's been imprisoned now since last summer. I'm not sure how open he feels he can speak with the Swiss, given his situation. I'm taking everything with a grain of salt."

The relationship between Iran and the U.S. has become increasingly tense since President Trump took office. Mr. Trump withdrew from the Iran nuclear deal negotiated by former President Barack Obama.

"It's unclear if he's an unfortunate foreigner caught in a different legal system or if he's being used as a political pawn because of the bad relations between the two countries, or a combination of the two, I suppose," Zaid said.

White is the first American imprisoned in Iran since Mr. Trump took office. Americans Siamak Namazi, Baquer Namazi and Xiyue Wang are also imprisoned in Iran on charges of spying, which they deny. Robert Levinson, another American, has been missing in Iran since 2007.

Roxana Saberi contributed reporting.