Former Secretary of State Hillary Clinton said Thursday that the U.S. military should strike Syrian President Bashar Assad’s air force in response to this week’s chemical attack that killed more than 70 civilians.

Clinton, the 2016 Democratic nominee, said at the Women in the World summit in New York City that a retaliatory strike would prevent Assad from carrying out similar attacks in the future.

“Assad has an air force, and that air force is the cause of most of these civilian deaths as we have seen over the years and as we saw again in the last few days,” Clinton said. “And I really believe that we should have and still should take out his air fields and prevent him from being able to use them to bomb innocent people and drop sarin gas on them.”

U.S. officials believe Assad’s regime is responsible for Tuesday’s sarin gas attack on the opposition-held town of Khan Skeikhoun.

Hours after Clinton’s remarks, the U.S. began striking targets in Syria.

ANGELA WEISS via Getty Images Hillary Clinton said the U.S. should "take out" the Syrian regime's airfileds.

Clinton also restated her support for a no-fly zone in Syria, a policy she defended throughout the 2016 campaign.

“I still believe we should have done a no-fly zone,” she said. “We should have been more willing to confront Assad.”

The administration of former President Barack Obama’s administration, in which Clinton served, asked Congress to authorize the use of force against the Syrian regime in 2013, but legislators never voted on the request.

President Donald Trump has appeared to reverse course this week after years of opposing intervention in the Syrian conflict, which has left more than 207,000 civilians dead since 2011. While his administration previously said removing Assad from power was no longer a goal, Trump this week said “something should happen” in response to the chemical attack.

Trump said his shift came after he saw video of the attack.

“That attack on children yesterday had a big impact on me. Big impact. That was a horrible, horrible thing,” he said. “And I’ve been watching it and seeing it, and it doesn’t get any worse than that. And I have that flexibility, and it’s very, very possible, and I will tell you, it’s already happened, that my attitude toward Syria and Assad has changed very much.”

This article has been updated to note the U.S. strike on Syria.