Moscow also demanded an emergency meeting of the U.N. Security Council to discuss the U.S. missile strike.

The United Nations Security Council will meet at 1130 EDT (1530 GMT) on Friday to discuss Thursday’s U.S. cruise missile strikes on Syria, diplomats said.

The meeting of the 15-member council will be public, diplomats said.

The Russian Defence Ministry on Friday said the Syrian air defences would be beefed up after U.S. cruise missiles struck an airfield in western Syria, Russian news agencies reported.

Earlier in the day, the U.S. forces fired a barrage of cruise missiles at the Syrian airfield early on Friday in response to what President Donald Trump called a “barbaric” chemical attack on a rebel held town he blamed on the Damascus regime.

Moscow also demanded an emergency meeting of the U.N. Security Council to discuss the U.S. missile strike, calling it a “gross... violation of international law.”

The Kremlin said President Vladimir Putin considered it an "aggression against a sovereign state" and that it would inflict "considerable damage" on the U.S.-Russia ties.