Defense Secretary Jim Mattis said Monday morning that a U.S. response was possible to the Syrian regime’s reported chemical weapons attack over the weekend.

“I don’t rule out anything right now,” Mattis told reporters during a meeting with a Qatari official at the Pentagon.

The secretary also pointed to Russia’s responsibility in the attack by Syrian President Bashar Assad's government Saturday evening that killed dozens, including women and children, in a rebel-held suburb of Damascus. It comes a year after the U.S. struck Syria with cruise missiles for a similar chemical weapons attack on rebels and civilians.

“The first thing we have to look at is, why are chemical weapons still being used at all when Russia was the framework guarantor of removing all the chemical weapons?” he said. “And so, working with our allies and our partners from NATO to Qatar and elsewhere, we are going to address this issue.”

On Sunday night, news reports suggested that the U.S. had begun conducting airstrikes in Syria, but the Pentagon later denied taking any action. Russia has blamed Israel for the counter attacks on a Syrian military base by fighter jets.

Mattis made his comments just as President Trump's National Security Council is set to meet to today and the U.N. Security Council has an emergency meeting scheduled.

The president is scheduled to receive a briefing from senior military leaders at 6 p.m. Monday, followed by dinner with those leaders.

Trump warned of harsh consequences for the attack in a tweet on Sunday that called Assad an "animal" and criticized Russian President Vladimir Putin by name.

“Many dead, including women and children, in mindless CHEMICAL attack in Syria. Area of atrocity is in lockdown and encircled by Syrian Army, making it completely inaccessible to outside world. President Putin, Russia and Iran are responsible for backing Animal Assad,” Trump tweeted. “Big price to pay. Open area immediately for medical help and verification. Another humanitarian disaster for no reason whatsoever. SICK!”



Many dead, including women and children, in mindless CHEMICAL attack in Syria. Area of atrocity is in lockdown and encircled by Syrian Army, making it completely inaccessible to outside world. President Putin, Russia and Iran are responsible for backing Animal Assad. Big price... — Donald J. Trump (@realDonaldTrump) April 8, 2018