U.S.' Bolton: Russia missile sale to Syria is 'significant escalation'

U.S. National Security Adviser John Bolton said on Monday that Russian plans to supply Syria with an S-300 missile system would be a "significant escalation" by Moscow and hopes it will reconsider.

Russia announced on Monday it will supply the surface-to-air missile system to Syria in two weeks against strong Israeli objections, a week after Moscow blamed Israel for indirectly causing the downing of a Russian military plane in Syria. (Reporting by Jeff Mason Editing by Mary Milliken and Grant McCool)