Marco Rubio is juggling his roles as both Secretary of State and National Security Adviser. President Trump suggested Stephen Miller could be up for the role of NSA. NBC News' Courtney Kube joins Katy Tur to report more from the Pentagon.

U.S. President Donald Trump said on Sunday that Stephen Miller, his deputy chief of staff, was a frontrunner to be potentially named as national security adviser following the departure of Mike Waltz.

President Trump confirmed late Sunday that deputy chief of staff for policy Stephen Miller is at the top of his list of possible contenders to permanently fill the role of national security