The President of the United States has numerous powers, including those explicitly granted by Article II of the United States Constitution.
The Constitution explicitly assigned the president the power to sign or veto legislation, command the armed forces, ask for the written opinion of their Cabinet, convene or adjourn Congress, grant reprieves and pardons, and receive ambassadors. The president may make treaties which need to be ratified by two-thirds of the Senate. The president may also appoint Article III judges and some officers with the advice and consent of the U.S. Senate. In the condition of a Senate recess, the president may make a temporary appointment.
Within the executive branch itself, the president has broad powers to manage national affairs and the priorities of the government. The president can issue rules, regulations, and instructions called executive orders, which have the binding force of law upon federal agencies but do not require approval of the United States Congress. Executive orders are subject to judicial review and interpretation.
The Budget and Accounting Act of 1921 put additional responsibilities on the presidency for the preparation of the United States federal budget, although Congress was required to approve it. The act required the Office of Management and Budget to assist the president with the preparation of the budget. Previous presidents had the privilege of impounding funds as they saw fit, however the United States Supreme Court revoked the privilege in 1998 as a violation of the Presentment Clause. The power was available to all presidents and was regarded as a power inherent to the office. The Congressional Budget and Impoundment Control Act of 1974 was passed in response to large-scale power exercises by President Nixon. The act also created the Congressional Budget Office as a legislative counterpoint to the Office of Management and Budget.