The contact with Russia on Syria proved its efficiency in the Hasakah area last week, Pentagon spokesman Peter Cook said.
"We communicated through the Russians to explain our concerns about what happened last week. And we think that was communicated effectively," Cook said, adding that the US would defend coalition forces on the ground.
"And that is an area in which we've been active. We've been clear about that. And so, we're going to continue to defend our forces in that area. We're going to tell the Syrians and anyone else who may threaten our forces in that area, we will defend them," he explained.
According to Cook, that's the message they sent to the Syrian authorities.
