On Thursday, Secretary of Defense James Mattis told the Senate Armed Services Committee that he ordered Russian mercenaries in Syria to be annihilated once he found out that they were not part of the Russian military.

Mattis revealed that the military used a deconfliction line with Russia to make sure that forces with which they were engaged in conflict were not part of the Russian military. Once the military received confirmation from Russia, Mattis ordered U.S. military forces to destroy the Russian mercenaries, The Washington Free Beacon reported.

“The Russian high command in Syria assured us it was not their people, and my direction to the chairman was for the force, then, to be annihilated,” Mattis said. “And it was.”

Mattis added that at this point he couldn’t attribute responsibility for who was behind the Russian mercenaries to the Russian government, noting that there are multiple forces involved in the operations in Syria.

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