Ambassadors of the United States are persons nominated by the president to serve as the country's diplomatic representatives to foreign nations, international organizations, and as ambassadors-at-large. Under Article II, Section 2 of the U.S. Constitution, their appointment must be confirmed by the United States Senate; while an ambassador may be appointed during a recess, they can serve only until the end of the next session of Congress, unless subsequently confirmed.

The United States Senate is the upper chamber of the United States Congress. The United States Senate and the lower chamber of Congress, the United States House of Representatives, comprise the federal bicameral legislature of the United States. Together, the Senate and the House maintain authority under Article One of the U.S. Constitution to pass or defeat federal legislation. The Senate has exclusive power to confirm U.S. presidential appointments, approve or reject treaties, and try cases of impeachment brought by the House. The Senate and the House provide a check and balance on the powers of the executive and judicial branches of government.