Pentagon says it's aware of reports on new 'exchange of fire' in Syria

A senior Pentagon official said on Wednesday he was aware of reports of a new "exchange of fire" in Syria, a day after the U.S. military announced a series of air strikes in the country against facilities used by Iran-aligned militia.

"We'll tell you more when we know more," Colin Kahl, undersecretary of defense for policy, told a news briefing, adding that the U.S. military would not hesitate to defend its personnel.