The U.S. government on Saturday urged American citizens to leave Iran immediately if possible and advised citizens not already in the country not to travel there for any reason because of the growing danger as hostilities continue between Iran and Israel.

"U.S. citizens who are unable to depart Iran should be prepared to shelter in place for extended periods," read an advisory posted Saturday by the U.S. Virtual Embassy for Iran. "U.S. citizens in Iran face serious, increasing dangers due to rising regional tensions."

Further, the advisory warned the U.S. government does not have diplomatic or consular relations with the Islamic Republic of Iran and said that the Swiss government, through its embassy in Tehran, will serve as the protecting power for U.S. interests in the country.

The government also warned as of Saturday, Iran's airspace remains closed and said U.S. citizens wishing to leave by plane should confirm their travel plans with their airlines.

The advisory said as for now, Iran's borders with Armenia and Turkey remain open. However, it said the Iranian government may restrict non-Turkish nationals from crossing the border and flights out of Turkey have limited availability.

U.S. citizens in Iran were also told they must have a plan to leave Iran that does not rely on help from the U.S. government and to make plans for sheltering in a safe location if they cannot leave.

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