Donald Trump
Donald TrumpReuters

U.S. President Trump told reporters that a decision on a course of action against Syria, following the weekend’s suspected chemical attack, could come as soon as Monday night.

Speaking to reporters and quoted by Fox News, the President promised that the United States would respond "forcefully" to the attack in Syria.

"We're making a decision as to what we do with respect to the horrible attack that was made near Damascus, and it will be met and it will be met forcefully," Trump said at the top of a meeting with top military leaders at the White House.

"When, I will not say because I don’t like talking about timing," he added, though he said the group was "going to make a decision tonight or very shortly thereafter and you'll be hearing the decision."

Earlier on Monday, Trump said the chemical attack in Douma was "atrocious" and "horrible" and added that the U.S. would make "major decisions" about its response over the next 24 to 48 hours.

The meeting's attendees included Vice President Mike Pence, Defense Secretary Jim Mattis and the chairman of the Joint Chiefs of Staff, Gen. Joseph Dunford

Trump said the group was "going to make a decision tonight or very shortly thereafter and you'll be hearing the decision."

Saturday's suspected poison gas attack included use of sarin nerve gas, the UK-based Syrian Observatory for Human Rights reported. The claim was later independently confirmed by U.S. intelligence agencies.

"We can't let atrocities like we all witnessed … happen in our world," Trump said Monday night, "especially when we’re able to -- because of the power of the United States, because of the power of our country -- we’re able to stop it."

Earlier on Monday, U.S. Ambassador to the UN Nikki Haley addressed the Security Council and said the United States would respond to the Syrian attack even if the UN does not.

“Only a monster targets civilians and then ensures that there are no ambulances to transfer the wounded. No hospitals to save their lives. No doctors or medicine to ease their pain. I could hold up pictures of all of this killing and suffering for the Council to see, but what would be the point? The monster who was responsible for these attacks has no conscience, not even to even be shocked by pictures of dead children,” Haley said.

“We are beyond appeals to conscience. We have reached the moment when the world must see justice done. History will record this as the moment when the Security Council either discharged its duty or demonstrated its utter and complete failure to protect the people of Syria. Either way, the United States will respond,” she added.