The democratic presidential hopeful said the Syrian ruler should be held accountable "if the evidence is there" on chemical weapons.
Government officials claim insurgents were behind the gas attack, but rebel groups have called the allegations "purely a lie."
The attack in February left 11 people in need of emergency treatment.
The cynicism Americans feel about humanitarian intervention makes sense. But we must stand in solidarity with Syrians.
The U.S. also said Russians or Syrians may have tampered with evidence on the ground. Moscow denied the charge.
U.S. President Donald Trump launched the strikes in response to a deadly chemical attack near Damascus.
“Could not have had a better result,” said President Donald Trump. “Mission Accomplished!”
The strikes, led by the U.S., U.K. and France, targeted three facilities associated with Syria’s chemical weapons program.
Trump ordered military strikes on Syria in response to the attack.
A chemical attack on a rebel-held town in eastern Ghouta was said to have killed at least 49.
The chemical weapon was developed in secret in the Soviet Union in the 1980s.
The "brave new world" of computer warfare -- in all its frightening aspects -- desperately needs some rules and limits. Communications spying and drone attacks are only the precursors for what could be eventually deployed against the United States.
The current debate on the use and ban of chemical weapons in Syria is a salient testimony to a seemingly forgone notion in crisis diplomacy: the downward spiral of conflict doesn't end until the strategic interests of the key players are addressed.
Police in Long Beach, Calif. released horrifying footage of a Molotov cocktail attack in the hopes of catching the culprit