The United States has urged its citizens in Iran to leave the country following the partial reopening of Iranian airspace and the resumption of some flights.

In a security alert issued by the U.S. Virtual Embassy in Tehran, officials said: “Iranian airspace has been partially reopened as of April 21, and U.S. citizens should depart Iran immediately.”

The advisory also urged Americans to monitor local media and contact airlines for updated information on outbound flights.

It noted that those wishing to leave Iran may travel overland to Armenia, Azerbaijan, Turkey, or Turkmenistan, while warning against travel to border areas with Afghanistan, Iraq, or Pakistan.

The U.S. has not maintained a diplomatic mission in Iran since the 1979 hostage crisis, with Switzerland representing American interests in Tehran.

The warning comes amid ongoing tensions despite a temporary ceasefire announced on April 8 through Pakistani mediation.