Russia committed not to attack moderate Syrian groups - U.S. official

WASHINGTON (Reuters) - Russia has committed not to launch strikes against Syrian groups the United States considers to be part of the moderate opposition, the U.S. State Department said on Friday, hours before a cessation of hostilities in Syria was due to start. It is "put-up or shut-up time" for Russia, which supports the Syrian government, to show whether it is serious about halting the fighting, State Department spokesman Mark Toner said in a news briefing. (Reporting by Arshad Mohammed; Editing by Mohammad Zargham and Paul Simao)