Rubio referred to Iran's long-standing practice of "arresting innocent Americans, as well as citizens of other countries, with the aim of using them as a means of pressure on other states."
If Iran does not stop, the United States will take further measures such as travel bans, Rubio added.
"No American citizen should travel to Iran for any reason. We reiterate our call for Americans who are in Iran to leave the country immediately," Rubio continued.
