An Iranian court has sentenced an American to 10 years in prison for insulting the country's supreme leader and posting a private picture, his lawyer confirmed on Saturday.

Michael White, 46, a 13-year US Navy veteran, was arrested in July in the northeastern Iranian city of Mashhad while visiting a girlfriend he reportedly met online.

His lawyer Mark Zaid confirmed that White was sentenced to two years for insulting Supreme Leader Ayatollah Ali Khamenei and 10 years for posting a picture, apparently to be served concurrently.

“We remain very concerned about his health as he has pre-existing medical conditions but we've been informed he appears to be in a good state at the moment,” Zaid said in an email.

The New York Times, which first reported the sentencing, said White had been given two court hearings, on March 6 and March 9.

The State Department was informed of the sentencing by Swiss diplomats who represent US interests in Iran, according to Zaid, who said White has not been allowed to communicate directly with his family.

White's family has said he traveled to Iran on a valid visa to visit a woman with whom he had fallen in love.

White was the first American to be detained in Iran since Donald Trump became president of the United States.

Three other Americans imprisoned in Iran — Siamak Namazi, Baquer Namazi and Xiyue Wang — have been accused of spying and sedition. A fourth, Robert Levinson, has been missing in Iran since 2007.