U.S. Embassy in Ukraine urges Americans who can to flee the country immediately

Washington — The U.S. State Department on Monday issued a security alert warning that Russia is stepping up efforts to launch strikes against Ukraine's civilian infrastructure and government facilities in the coming days and urging U.S. citizens still in Ukraine to depart the country immediately.

"The U.S. Embassy urges U.S. citizens to depart Ukraine now using privately available ground transportation options if it is safe to do so," the alert said.

"If you hear a loud explosion or if sirens are activated, immediately seek cover," the State Department said in its alert. "If in a home or a building, go to the lowest level of the structure with the fewest exterior walls, windows, and openings; close any doors and sit near an interior wall, away from any windows or openings."