Simplify the following text for a Grade 17 native English-speaking person.
Original: The White House National Security Council ( NSC ) in the United States is the principal forum used by the President of the United States for considering national security and foreign policy matters with his senior national security advisors and Cabinet officials and is part of the Executive Office of the President of the United States .
Simplified: The White House National Security Council ( NSC ) in the United States is the principal forum used by the President for considering national security and foreign policy matters with his senior national security advisors and Cabinet officials and is part of the President 's Executive Office .