WASHINGTON (Reuters) - U.S. Secretary of State John Kerry is expected to make a statement at 12:30 p.m. EDT on Friday about Syria, a U.S. government source said.

The United States is deliberating about action to punish Syrian President Bashar al-Assad's government for an apparent poison gas attack on civilians. The momentum for a decisive strike slowed after a British parliamentary vote on Thursday against it.

(Reporting by Mark Hosenball; Editing by Vicki Allen)