US says Islamic State video of journalist's killing is authentic

An Islamic State video showing the beheading of American journalist Steven Sotloff in reprisal for U.S. air strikes in Iraq is authentic, U.S. National Security Council spokesperson Caitlin Hayden said on Wednesday.

"The U.S. Intelligence Community has analyzed the recently released video showing U.S. citizen Steven Sotloff and has reached the judgment that it is authentic," Hayden said in a statement.

U.S. President Barack Obama is in Estonia ahead of a NATO summit in Wales later this week.

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