U.S. citizens should consider leaving Russia immediately on commercial flights, the State Department said on Sunday, citing an increasing number of airlines canceling flights and countries closing their airspace to Russia after its invasion of Ukraine, Reuters reported.

It has asked U.S. citizens to have "a contingency plan that does not rely on U.S. government assistance."

The State Department has kept its travel advisory for Russia at "Level 4: Do Not Travel".

On February 20, the U.S. embassy in Moscow had advised Americans in the country to have an evacuation plan, citing the threat of attacks in Moscow and along the Russian border with Ukraine.