"President Trump is prepared to impose new and serious consequences on Iran unless all unjustly imprisoned American citizens are released and returned," the administration said Friday evening.
New punitive measures will be applied against Iran if the nation's leaders do not send home all US nationals.
Washington maintains that its citizens are being held unjustly. "For nearly 40 years, Iran has used detentions and hostage taking as a tool of state policy, a practice that continues to this day to with the recent sentencing of Xiyue Wang to ten years in prison," the White House said.
Wang is a Chinese-born American who was recently charged with espionage. Wang, 37, was a graduate student at Princeton studying history prior to detention.
"President Trump urges Iran to return Robert Levinson home," the statement noted.
Levinson worked for the FBI before retiring in 2007, the same year he traveled alone to Iran. Political expert Mojtaba Jalalzadeh of the Islamic Azad University based in Iran's capital told Spuntik Persia, "later it became known that he maintained close ties with the FBI and arrived to Iran on a spy mission."
Siamak and Baquer Namazi are also included in Washington's list of demands.