TEHRAN (Press Shia) – US President Donald Trump on Monday promised quick, forceful action in response to an alleged chemical weapons attack in Syria.

Speaking at a meeting with military leaders and national security advisers, Trump said he would make a decision by Monday night “or very shortly thereafter” on a response, adding that the United States had “a lot of options militarily” on Syria, Reuters reported.

“But we can’t let atrocities like we all witnessed … we can’t let that happen in our world … especially when we’re able to because of the power of the United States, the power of our country, we’re able to stop it.”

An alleged chemical attack on Saturday in the militant-held town of Douma in Eastern Ghouta reportedly left dozens dead.

Initial US assessments have so far been unable to determine conclusively what materials were used in the attack and could not say with certainty that the Syrian government was behind it.

Trump said, however, that Washington was “getting more clarity” on who was responsible for the attack.

Asked at a Cabinet meeting earlier on Monday if Russian President Vladimir Putin bore any responsibility for the attack, Trump said, “He may, yeah, he may. And if he does, it’s going to be very tough, very tough.”

On Sunday, the US president who had sought warmer relations with Russia criticized Putin by name on Twitter as he castigated Russia and Iran for backing “Animal Assad.”

The US envoy to the United Nations, Nikki Haley, said Washington “will respond” to the attack regardless of whether the UN Security Council acts or not.

Moscow said it warned the United States of “grave repercussions” if it carried out an attack against Syria.

The Syrian government and its ally Russia have denied involvement in the attack.