Russia had advanced knowledge of last week's chemical attack in Syria, senior U.S. officials have concluded. The attack in the Idlib province killed dozens of civilians, including children, and prompted President Trump to order a retaliatory missile strike on a Syrian airfield last Thursday.

Officials were initially unsure whether Russia or Syria operated the drone that flew over a hospital where victims of the chemical attack were being treated, but it's now believed it was controlled by Russia. An official told The Associated Press that "the presence of the drone couldn't have been a coincidence, and that Russia must have known the chemical weapons attack was coming and that victims were seeking treatment."

Officials also revealed that the fighter jet that later bombed the hospital was Russian-made, though it's not yet clear if it was operated by Russia or Syria. The bombing, which happened hours after the drone left the scene, is believed to be "an attempt to cover up the usage of chemical weapons," The Associated Press reported.

The White House has blamed Syrian President Bashar al-Assad for the chemical attack. Becca Stanek