The White House on Thursday said that Brooke Anderson will serve as Chief of Staff and Counselor for the National Security Staff at the White House beginning on January 12. According to a statement released by the White House Press Office, Anderson, who is currently serving as Ambassador and Alternate Representative for Special Political Affairs at the U.S. Mission to the United Nations, will take over the post from Denis McDonough who was named deputy national security advisor in October. National Security Advisor Tom Donilon said, "Brooke Anderson is an extraordinarily talented, experienced, and well-respected member of our Administration. Her deep expertise on issues ranging from non-proliferation to the United Nations, along with her broad experience in and out of the U.S. government, make her the ideal person to serve as chief of staff here and counselor to the National Security Staff." While at the U.S. Mission to the U.N., Anderson has focused on U.N. Security Council matters, including U.N. peacekeeping missions and nonproliferation. Anderson has over 20 years experience working in the public policy arena - as a Senior Director at the White House National Security Council and in senior leadership positions at the U.S. Department of Energy, in the U.S. Congress and in the nonprofit and private sector, the White House said. Anderson also served as Chief of Staff and Counselor to Ambassador Susan Rice. Prior to joining the U.S. Mission, Anderson was Chief National Security Spokesperson and Policy Advisor for the Obama-Biden Transition. She was also member of the White House National Security Council Transition Team, advising on the National Security Council structure and policy agenda, the White House said.