The US State Department said on Tuesday it was aware of reports of the detention of a US citizen held in Iran for more than six months, amid heightened tensions between the countries following the reimposition of US sanctions.
The US State Department said it was "aware of reports" of the detention but declined details, citing privacy considerations.
White, 46, was detained in Iran after visiting his Iranian girlfriend, his mother told the New York Times on Monday.
His mother, Joanne White, told the newspaper the 46-year-old veteran went to Iran to see his girlfriend and had booked a July 27 flight back home to San Diego via the United Arab Emirates. Lupe White said he has had an online relationship with a woman in Iran for six years and would go see her for two weeks at a time.
"All I know is that he is alive and they were putting in a request for a consular visit by the Swiss".More news: Serena Williams' legacy secure despite infamous US Open umpire row: Chris Evert
According to the Times, there are at least three other Americans now being detained in Iran.
She said she is anxious about his health, because he has had cancer and suffers from asthma. He met her online about four or five years ago, and he had visited her four times over the last few years, Joanne White said.
Tension between Iran and the United States has risen significantly since last May, when US President Donald Trump withdrew from an worldwide nuclear deal with Tehran and reimposed US sanctions that had been lifted after a 2015 accord.
At least three other US citizens have been incarcerated in Iran for years.
She shortly filed a missing-person report with the State Department, prompting the Department of Homeland Security to contact her.More news: Michael Jackson sex abuse: Leaving Neverland at Sundance features 'new victims'
Iran is also holding at least three other prisoners: Siamak and Baquer Namazi, an Iranian-American father and son who were convicted in a closed-door trial after being arrested in February 2016, and Xiyue Wang, a grad student at Princeton who was arrested in August 2016.
The Iranian-run outlet based its report on a former Iranian prisoner who said he met the American in Vakilabad Prison in the city of Mashhad back in October past year.
The New York Times noted that Iran did not acknowledge the arrest of Wang until July 2017. Iranian officials have repeatedly denied knowledge of his disappearance or whereabouts.
In December, six families of foreign or dual nationals held or believed to have disappeared in Iran - including the families of the Namazis and Levinson - issued an open letter alleging their relatives were political hostages detained without due process.
Iran has released Americans and other foreign nationals in recent years.More news: Image gallery: New-gen Mercedes-Benz CLA at CES 2019
The last time Iran released USA citizens from its prisons was when the nuclear agreement took effect in January 2016.
- 'Gully Boy' trailer: Ranveer and Alia steal the show
- Iran Confirms It's Holding U.S. Navy Veteran
- Adam Gase to Become New York Jets' Head Coach
- How Much Could Wife of Amazon's Jeff Bezos Get in Divorce?
- SABC to continue playing R Kelly's music, for now
- Manny Pacquiao and Floyd Mayweather meet again at Clippers game
- Jazmine Barnes: Second man charged in drive-by shooting
- Packers hire LaFleur as head coach
- Rare 1943 copper coin could fetch a pretty penny in auction
- Prince Harry and Meghan Markle's Cotswold country weekender has been revealed