(CN) – President Donald Trump on Monday condemned the “atrocious” suspected poison gas attack in Syria and said he’ll make a decision on retaliatory U.S. air strikes within 24 to 48 hours.
“It was an atrocious attack, it was horrible,” Trump said before a White house cabinet meeting Monday morning. “This is about humanity and it can’t be allowed to happen.”
The president went on to vow to find out who is responsible for the attack that reportedly killed at least 40 people.
Trump said during a Cabinet meeting with reporters that, “If it’s Russia, if it’s Syria, if it’s Iran, if it’s all of them together, we’ll figure it out.”
Opposition activists said 40 people died in the chemical attack late Saturday in the suburbs of the Syrian capital and blamed it on the Syrian government, which is closely allied with Russia.
Syria has blamed Israel for a missile attack on a central air base early Monday that reportedly killed 14 people, including three Iranians.
At the Pentagon, Defense Secretary Jim Mattis told reporters earlier on Monday that the U.S. is not ruling out military airstrikes against Syria.
During a photo-taking session in the Pentagon before a meeting with the emir of Qatar on Monday, Mattis said the Trump administration is consulting with allies in Europe, the Middle East and elsewhere.
Asked by a reporter about a possible U.S. military response, Mattis said, “I don’t rule out anything right now.”
Mattis also said the “first thing” the administration is considering is why chemical weapons are being used at all in Syria. Russia was a guarantor of a deal the Obama administration struck in 2013 in which Syria was to have removed all of its chemical weapons. Mattis added that the administration will work with other countries to “address this issue.”
The Associated Press contributed to this report.