Kirby 'confident' Americans in Gaza will be freed Sunday amid reports of Israel, Hamas deal holdup

White House national security communications adviser John Kirby said Thursday morning that he is "confident" that a cease-fire and hostage exchange deal can still be "implemented" Sunday as families of two Americans slated for immediate release await answers. 

"There's a deal," Kirby told ABC’s George Stephanopoulos. "We're confident that we're going to be able to start implementing it on Sunday. There are some implementing details that still need to be ironed out. We're working with the Israelis on that very, very hard right now.