The United States has denied any role in the deadly missile strike on a Syrian military airport, after the US and France warned of a strong response to, what they alleged, "horrific chemical weapons attacks" on a rebel-held area near Damascus.
A barrage of missiles struck Syria's central Tayfur air base, just hours ahead of an urgent UN meeting over the alleged use of toxic gas on the town of Douma.
US President Donald Trump and his French counterpart Emmanuel Macron had on Sunday vowed a "strong, joint response" to the alleged chemical attack that killed dozens
The White House also on Sunday said the regime of Syrian President Bashar al-Assad "must be held accountable for its continued human rights abuses".
Trump had earlier taken to Twitter to issue a blistering warning to the Syrian regime and its allies.
"Many dead, including women and children, in mindless CHEMICAL attack in Syria," Trump wrote, lashing out at Russia's Vladimir Putin, a key ally of the regime.
The United Nations Security Council will meet soon following rival requests by Russia and the United States in the wake of the chemical attack and missile strike that followed.
A joint statement by the medical relief organization Syrian American Medical Society (SAMS) and the civil defense service, which operates in rebel-held areas, said 49 people had died in the attack late on Saturday in the town of Douma.
US President Donald Trump had warned that there would be a “big price to pay,” for Syria and its supporters.
Russia called for a meeting of the 15-member council on “international threats to peace and security,” though the precise topic of discussion was not immediately clear, diplomats said on Sunday.
A minute later the United States, France, Britain, Sweden, Poland, the Netherlands, Kuwait, Peru and Ivory Coast called for a meeting to discuss the chemical weapons attack in Syria, said diplomats who saw the email requests.
An agreement was reached late Sunday to hold one meeting on Monday instead of two, diplomats said.
“The Security Council has to come together and demand immediate access for first responders, support an independent investigation into what happened, and hold accountable those responsible for this atrocious act,” US Ambassador to the United Nations Nikki Haley said in a statement on Sunday.
Haley warned last month that if the UN Security Council fails to act on Syria, Washington “remains prepared to act if we must,” just as it did last year when it bombed a Syrian government air base over a deadly chemical weapons attack.