Ghasemi denied allegations that White, who hails from Imperial Beach, California, has been mistreated in prison.
"The case of this person is being handled by the relevant authorities and at the conclusion of this process they will issue the necessary information", Ghasemi was further quoted as saying on his Telegram account.
According to Farhadi, White said he became acquainted with an Iranian girl online and traveled to Iran three times to visit her.
"An American Citizen, named Michael White was arrested a while ago in the city of Mashhad", the spokesperson for Iran's Ministry of Foreign Affairs said, according to the Islamic Republic News Agency.
He also noted that Tehran informed the U.S. during the first days of Michael White's arrest.
"I'm very anxious about his health", she said, according to CBS News. "They are being kept from their families, and they need to come home".
"His arrest was communicated early through Interests Section of The Islamic Republic of Iran to the U.S. government".
Scientists detect mysterious radio signals in space
A telescope in Canada picked up mysterious signals emanating from a distant galaxy. Knowing that there is another suggests that there could be more out there.
"We have no higher priority than the safety and security of USA citizens overseas".
Since October 2015, it has also been holding Iranian-American Siamak Namazi. The son was held while visiting relatives in Tehran; both were sentenced in 2016 to 10 years in prison for what the Iranian government said was "cooperating with Iran's enemies", which usually implies cooperating with the United States.
The network reported that it learned that Iran suggested a possible prisoner exchange previous year, but State Department officials will not say whether the Trump administration is willing to negotiate.
White joins at least three other United States citizens, two of them of Iranian descent, in Iranian detention.
New details are emerging about an American Navy veteran being held captive in Iran.
In 2007, a former Federal Bureau of Investigation agent, Robert Levinson, went missing in Iran.
In January 2016, Iran freed four USA prisoners - Washington Post journalist Jason Rezaian, Marine veteran Amir Hekmati, Christian pastor Saeed Abedini and Nosratollah Khosravi-Roodsari - in exchange for the U.S. granting clemency to seven Iranians indicted or imprisoned in the United States.
President Donald Trump withdrew from an worldwide agreement Iran's nuclear programme and re-imposed sanctions previous year that hit the Iranian economy hard.