"Today, President Trump signed an Executive Order that takes unprecedented action to impose new consequences on those who wrongfully detain Americans abroad," Marco Rubio said on Friday.
"Through this Executive Order, actors designated as State Sponsors of Wrongful Detention may face severe penalties including economic sanctions, visa restrictions, foreign assistance restrictions, and travel restrictions for US passport holders," he added.
The statement did not specify any particular country or group, but a notice on the State Department's Office of the Special Presidential Envoy for Hostage Affairs strongly warns Americans against visiting Iran over the risk of wrongful detentions.
"Americans, including Iranian-Americans and other dual nationals, have been wrongfully detained, taken hostage by the Iranian government for months, and years," the department says in its travel advisory.
"The threat of detention is even greater today, do not travel to Iran under any circumstances."
Last month, the State Department advised citizens against traveling to Iran citing what it called escalating paranoia and an unprecedented crackdown on alleged spies and opponents following a 12-day war with Israel.
"The Iranian regime, following the 12-day war with Israel, is in the midst of unprecedented paranoia and a crackdown on spies and regime opponents," the State Department said in a post on its Persian X account USA Beh Farsi.