Transcript for Trump continues to face backlash over troop pullout in Syria

President trump also facing new fall out over his decision to withdraw troops from Syria. A second member from his administration who is key to the fight against ISIS is stepping down because of this move. Now the president is fighting back. Lana Zak is at the white house. Reporter: Overnight president trump reacting to the resignation of Brett Mcgurk. After the top U.S. Envoy to the global coalition to defeat ISIS said he could not carry out the president's orders to withdraw from Syria and maintain my integrity. The president hitting back in a flurry of tweets calling him a grand stander and down playing his resignation. President trump said if anyone else made his Syria decision that person would be the most popular hero in America blaming the fake news. Many of the fiercest critics of the decision are actually lies of the president. This decision is a disaster. Mcgurk made that point a few days ago. It would be reckless if we were to say we can just leave now. Reporter: Mcgurk's announcement comes on the heels of the resignation of secretary of defense James Mattis. Who in his resignation letter wrote we cannot protect our interests without maintaining strong alliances, the example Mattis specifically mentioned, Mcgurk's defeat ISIS coalition. As the U.S. Pulls out, there will be other players in the region who will rush in to fill the void, Syria, Saudi Arabia, Russia, Iran. All of this countries will have a vested interest in moving in. When the U.S. Moves out. Mcgurk planned to leave in February. He moved that up in protest. Still no word who might replace general Jim Mattis as secretary of defense. Meaning that the trump administration will have two major holes to fill in the new year in the global fight against terrorism. Lana, thank you. So much to talk about when it comes to politics this morning. Let's bring in Jon Karl who will be hosting "This week." Jon's in D.C. Jon, good morning. The resignations of Mcgurk and Mattis come on top of a government shutdown, a tanking stock market and swirling investigations of pretty much almost every area of Donald Trump's life. It's adding to the media story line about a presidency going off the rails. We're seeing big stories this morning in the "Washington post" and "New York Times." My question to you is, haven't we heard this story before? What if anything is different? Dan, you're right. We certainly have heard many times before major crisis, chaos in the west wing, disorder. Staff shake-ups, all of that. But I have to tell you this feels different. What you are seeing this time that I believe is different is you are seeing a parade of Republican senators, many of whom have been consistently loyal to this president, backing him up at every turn, raising questions about his leadership, particularly on the decision to withdraw from Syria, but also on the negotiations over the wall. I mean, vice president Mike pence went to capitol hill on Tuesday and made it clear to Republican senators in a closed lunch that the white house was fine with this plan to keep the government operating. Then suddenly two days later you have the president shutting the government down. There is some real concern expressed, not just in the media here, but concern by some of the president's strongest allies. Or what have been the president's strongest allies on capitol hill. That may be what's different this time. Let's drill down meantime on this government shutdown. You've got the president's acting chief of staff Mick Mulvaney on the show this morning. The two sides seem to be digging in. How do you see this thing ending? This is a big interview. It's Mulvaney's first interview since being named acting chief of staff. He's also the budget director. He's also a former conservative member of the house, one of the founding members of the freedom caucus, somebody who has been in favor of government shutdowns in the past to push his point. I frankly don't see how this ends any time soon. Democrats have made it clear they're in no mood to compromise on the wall. The white house led by Mulvaney as well as the president seem to be prepared to set in for a long showdown with Democrats. So it's unclear how this resolves. One idea that was interesting was on the pages of the "Washington post" newt Gingrich co-authoring an op-ed saying the president should be willing to provide a path to citizenship for the dreamers in exchange for funding for his wall. Maybe some grand compromise like that, but we're a long way from that happening. In the meantime more dysfunction in Washington. Jon Karl, thank you always great to see you, notwithstanding the aforementioned dysfunction. I want to remind everybody Jon has a big show. He's going to go one on one with Mick Mulvaney. Plus the power house round table debates another especially chaotic week in Washington. It's all coming up on "This week." Jon, thanks again. Let's get a check of the

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