Transcript for Mom joins ISIS, takes children with her

We're now going to head to Erbil Iraq where ABC's James long man has. And the insane story about an American father whose children young children at that time. And they were seven in three years old were kidnapped from his Florida home by their mother and taken to Syria. James good to be with you. Hide out idea this really is an insane story as he say we've just spoken. To buster real shake the father who is here in bill and wanting to find out what has happened to his children put every one of it to 2015. He comes home to is found any time in all land to find his wife is known only that. She has taken a newborn daughter Zahara and F four year old son Yusef. And has gone today if in the Islamic state the so called Islamic state in Syria. What follows is full years of anguish by Cyril on the phone trying desperately to get in touch. With his wife yes she does and he left for a full month he finds out from my family. That it's probably Syria that she's gone to be he's content putting two and two together because she had intimate it interest in the Islamic state. Before. Before going to he had put that out of his mind he can think for a minute that she was actually going to go. And then he he informed the FBI immediately when he discovers that she's gone and is without means for a full month until finally. Another post and Kohl's he's he's he told me he was driving down a highway in Florida when he gets this by and cool from. A man with an English and British accent in English sounding voice he says Tim are you Abu Yousef. While the review said regret the Colson and says yes the guys we a wife and children are here. They are safer here than they way we view and we want you to come we want you to join and come to live in the Islamic state. And before DA is what by several things he has to do is try to convince. The ice this operatives who he knows a watching the messages they he's sending to his wife that he is going to come. He's any doing that in order that they allow him to continue his contact with his wife and children and before you is she sending photographs. Pictures. Then messaging each other she's trying to convince him to come. But slowly and solely crisis realizes that he has no intention of joining he's policy will these messages by the way. To the FBI cooperating and we've been fully in the hope that somehow. They'll be able to be extracted. In the end she divorces him by his forces to divorce in we have seen. The contract that ice is draws up and analyze this court to force to divorce him CB marries. And then. The trail goes cold for months and months until just a month ago when he gets the message from her sister who she had traveled to -- his charity with. Saying that she has been killed in the latest fighting. The wife now we know a month ago was killed someone named by dues which is about at the center of the last sound devices have been reporting about the last two weeks. I'm and the two engine he understands have been injured. Bodily into today faces. And so he is desperate becomes a behave two bill and he wants to get in to Syria we had this message and we wanna find these kids. So we have been spending the last few days going from place to place going from official to official. Finding out any information we count about whether these children are among the thousands who have been evacuated from ice this is lost down. We have been we work basically just a few days ago shaking the gates of the main town with 40000 refugees are thinking to house those kids could be inside have a source that suggested. They may be that I was on the phone one states to the US counsel's office in Iran to try to get permission to get inside discount. It has been quite a story and still busts your rule does not neither if his children are alive or dead he's hoping against hope that they are and he wants to come in Syria to get. And my buddies doing what how did we have covered some insane stories in the past but this ranks right up there with some of the craziest that I've ever heard. A father's love the just. Will night. Will not be abated until he gets his children back what are the logistic that would go into trying to retrieve them. I mean he'll misty wants to get inside Syria but we witch hunt is a table lesser role it said. Bulls I'd believe it to be you could be killed cutting inside and that if we if you do find your kids if your kids our life and what are they gonna do. We view dead so he has been implicated now I don't think he's gonna make those efforts in all Americans by the way. All told very falsely by the US State Department under no circumstances make that Jenny inside Syria. And then for the moment he's in the prices of talking to Malloy is to try to coordinate with the US military that have been instances of Americans found inside Syria who have been in and lifted out. And that is a possibility if the children are identified. I'm but you can imagine he is just as desperate desperate nine every time you mentioned these two children you stiffens opera his face lights up and then he crumbles. Because the anguish that this man is going for it. One of his children's a her you know she has been brought up in Arabic. English is an even not good anymore you set thankfully he's been speaking to him when he was speaking to Amy found out and his English is OK but yet the Jenny that this man has been on. Is just unthinkable I think any parent watching. BI data children are now alone orphaned somewhere in Syria is just incredible so everyone is hoping that the children are in that but there is no real way of knowing just yet. Just remember practice at 40000 refugees are probably amongst them. 20000 of them are children we've been in these refugee camps it's basically kids every way so aid agencies are now having to go from child to child to what how. Who weigh these children off the loss we had there was a possibility that they may have been look being looked after. By group of British ice it's wife's well are they going to give up these children or do they think that they don't wanna give them over to the great in Fidel and they want to keep the kids mean. The whole thing is massively complicated but he has all the people on his sides. He's praying every day the man is a very in southern Muslim. His message to have repeatedly throughout this whole deal was this is not the right way you need to come out. All vices tire tracks that are you praying for high now now that you know that she's she's died he said I pray for ice is because I want ice is to understand this is not true Islam. He's he's a wonderful very sweet man and everyone's hearts go out to him I really hoping that this this story which has been acting comes to. A good and it an epic story indeed thank you James really in war there are always stories of heartbreak that this one. Takes it to another level.

This transcript has been automatically generated and may not be 100% accurate.