As reported by the Associated Press:
Congressional sources, speaking on condition of anonymity, said they have been told the administration plans to choose three sanctions. One would bar Syrian planes from flying over or landing in the United States. Another would prohibit new investments by U.S. oil companies in Syria. It was not clear whether other U.S. business operations in Syria would also be prohibited. Bilateral trade with Syria is about $300 million a year.
One source said the third penalty would be a ban on U.S. exports to Syria, other than food and medicine.
And we all know what happens when sanctions don't work.