KEILAR: New details on U.S. airstrikes in Syria that killed more than 100 fighters, many of them Russians. I want to bring in CNN Pentagon correspondent, Barbara Starr. Barbara, what are you learning?</s>BARBARA STARR, CNN PENTAGON CORRESPONDENT: Well, Brianna, there's actually been two sets of U.S. airstrikes when the so-called pro- regime, pro-Assad troops moved against positions where U.S. troops were located with their partner forces. I want you to check out this video. This is from the first encounter, the major encounter when U.S. war planes struck back in self-defense, they say, at these T-72 tanks and artillery pieces. And in the artillery strikes, you can actually see figures moving on the ground trying to run away. Whoever these people were, and it's widely believed some were Russian mercenaries, they began moving and firing against U.S. positions in southeastern Syria. The U.S. acting in self-defense. So the big question is, why are they doing this? The Russians have acknowledged there may be Russian citizens in this part of Syria, although not Russian regular forces. They are supporting the Assad regime. And they are beginning to squeeze up against the positions where the U.S. troops are. So the Pentagon forced to take action, they say, in self-defense, to protect themselves and protect U.S. troops in this area and some of the rebel fighters that the U.S. is supporting. It's an unsettling move because Defense Secretary Mattis still says days later he cannot figure out the motivation, why these pro-regime, potentially, Russian mercenaries moved against the U.S. Over 100 fighters killed in that first round of strikes. All indications are some were, indeed, Russians -- Brianna?</s>KEILAR: Wow. Barbara Starr, thank you so much. We are standing by now at the White House right now. President Trump is holding a meeting with members of Congress on infrastructure. We expect to hear the president talk about that. But is he going to address the Rob Porter scandal and his embattled chief of staff? Stay with us.
Russian Fighters Among 100 Killed in U.S Airstrikes in Syria