National security advisor Jake Sullivan said President Biden was doing what he could to "strengthen" the position of Ukraine before he leaves office.

Watch Major Garrett's full interview with National Security Adviser Jake Sullivan, a portion of which aired on Dec. 1, 2024 on "Face the Nation with Margaret Brennan."

Outgoing National Security Adviser Jake Sullivan denied reports that the Biden administration is considering returning nuclear weapons to Ukraine, after the country relinquished its stockpile three decades ago after the fall of the Soviet Union.