Transcript for US shoots down Syrian warplane

The situation growing more tense in Syria this morning after a U.S. Fighter jet shot down a Syrian warplane on Sunday. That's the first time the U.S. Has shot down a Syrian jet since the conflict began and the first U.S. Air-to-air shootdown in nearly two decades. Martha Raddatz has more details for us and joins us from Washington, good morning, Martha. Reporter: Good morning, robin. This is something U.S. Fighter pilots train for all the time, an air-to-air shootdown but the last time they actually executed this move was in Kosovo so this is a dramatic turn in Syria. The American f-18 fighter jet launched by a nearby carrier locked on to the Syrian jet after it dropped bombs on u.s.-backed rebel forces fighting ISIS. Firing that air-to-air missile and shooting the Syrian warplane out of the sky. The shootdown coming after the U.S. Warned the Syrians through the Russians to halt their assault on the forces. The U.S. Called the Russians on a hotline and said stop attacking, minutes later a Syrian jet rolled in and it continued to attack the sdf forces on the ground. Reporter: The U.S. Military said the shootdown was justified as part of the collective self-defense of coalition partner forces fighting ISIS but further complicating U.S. Relations with Russia which is backing the Assad regime. The best case here is that the Syrians and the Russians say, okay, we've pushed the U.S. As far as they can go and they've drawn a line and we're not going to cross this again. On the other hand if Mr. Putin decides to escalate it it becomes a potentially very dangerous confrontation between the U.S. And Russian military forces. Reporter: And this morning, the Russian foreign ministry is responding calling this an act of aggression by the united States and a direct breach of international law. David, this is something to watch carefully in the coming days. You'll be watching it, Martha Raddatz, our thanks to you. The search for answers after

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