President Donald Trump's national security adviser says Trump will confront Turkey's leader about his decision to buy a Russian air defense system when they meet Wednesday at the White House.
Robert O'Brien tells CBS' "Face the Nation" that the U.S. is "very upset" about Turkey's purchase of the Russian S-400 system.
O'Brien says if the NATO ally doesn't get rid of that system, Turkey will likely face U.S. sanctions. He says that's a message Trump will deliver to Turkey's president, Recep Tayyip Erdogan.
The U.S. says the S-400 is not compatible with NATO forces, could compromise the F-35 fighter jet program and aid Russian intelligence. The Trump administration removed Turkey from the F-35 program in July.
Trump is to meet with NATO Secretary-General Jens Stoltenberg on Thursday.