The Russian military is claiming that Israel carried out this missile attack on a Syrian airfield that's believed to have left 14 pro-government soldiers dead.
Syrian state TV reported multiple casualties in what they said believed was a suspected US missile attack on a military airport in the early hours of Monday.
Washington denied any involvement in the strikes on Tiyas airbase, located near Homs, which is a main base for Iranian-backed militias.
The strike comes amid international outrage over a purported chemical weapons attack in Douma, East Ghouta, on Saturday which left 70 people dead, including children.
The White House issued an official statement on Sunday condemning the attack and saying it would issue a "strong joint response" to the attack with France.
In tweets on his personal account, US President Donald Trump called Syria's President Bashar al-Assad an "animal".
The UN Security Council was to meet on Monday after the attack in Eastern Ghouta.
The Tiyas base — also referred to as T-4 — is in a strategic desert area on top of Syria's main gas fields are located.
It was under the control of Islamic State militants until the Syrian army and its allies regained control last year after heavy Russian military intervention.
Israel have refused to comment.