The Russia-brokered deal is backed by regional heavyweights Iran and Turkey. But it remains to be seen whether this deal will be any different than other truces that have failed to stop the violence.
The blacklisted people work on weapons development for Syria, the administration says. Treasury Secretary Steven Mnuchin says the sanctions "target the scientific support center" for the attack.
The Syrian Observatory for Human Rights says most of the victims were families evacuating from two Shiite villages, Fuaa and Kefraya, long besieged by rebels. No group has claimed responsibility.
From the White House press secretary's comparison of Hitler and Syria's President Bashar Assad to Trump's chocolate cake and dropping a bomb in Afghanistan, it was a heck of a week.
The U.S. intelligence community is confident the Syrian president used the nerve agent sarin against civilians. Assad, in an interview with the wire service, claimed the evidence is all fake.
The strike was requested by America's partners "who had identified the target location as an ISIS fighting position," U.S. Central Command said Thursday.
Before and after last week's chemical weapons attack, the Trump administration sent conflicting signals about foreign intervention, Russian cooperation and the fate of Syrian President Bashar Assad.
The White House released a declassified report on the attack in Khan Shaykhun. It says the U.S. is "confident" Syria's Bashar Assad was responsible and that Russia is attempting to deflect blame.