This type of powernot specifically mentioned in the Constitutionhas been argued to be essentially necessary for the President to fulfill all Constitutional responsibilities of the office. For example, President Bush has argued that the NSA wiretapping initiative is crucial to his responsibilities as Commander in Chief of the United States, protecting the physical security of the US and its people.

Inherent powers

Explanation:

Inherent Powers are said to be the powers that are not expressly defined or bestowed on the person using or applying the power to get things done.

Hence, in the case of the United States President, Inherent Power is the power or authority that President can use to get certain job done right or to perform his or her constitutional responsibilities.

It is to be noted that, these INHERENT POWERS are not specified in the Constitution, they are however considered to be reasonable powers delegated to the President to perform his duties in certain situations.