Transcript for The latest on Afghan peace talks

We're also following a major headline tonight that could affect thousands of American troops fighting in America's longest war. In Afghanistan. Tonight, negotiators for the U.S. And the Taliban have reached what is being called, quote, agreements in principle on key issues for a peace deal that could end 17 years of war in Afghanistan. Let's get right to Martha Raddatz, who has been to Afghanistan many times for us, and this comes from a top U.S. Envoy who acknowledged these meetings, these talks lasted far longer than anyone thought. And the acting defense secretary underscored this late today. Reporter: He certainly did. Patrick Shanahan said they were encouraging conversations. That may not sound like a big deal, but it is, it's very significant, given they've been after the Taliban and trying to get to some sort of peace agreement for so many years, 17 years. And the bottom line for folks watching at home is, what does this mean for the 14,000 U.S. Troops still there on the ground? Reporter: We already know that about 7,000 of those troops will come back. Shanahan was asked today whether he's been tasked with bringing them all back home, he said, no, he had not. But that doesn't mean it won't happen, David. All right, Martha Raddatz,

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