He takes an oath.
on this day, he gas to give his oath to the nation
The Vice President.
No, the president is not the Oath Of Office.
The vice president
When the president dies the Vice President takes office. In present times if Barack Obama would die Joe Biden would become president.
The President promises to protect the natural (and governed) rights of the people when he takes the oath of office.
If the president dies then the vice president takes office if the vice president dies then the speaker of office is president
The vice president becomes the president if the president dies. Such is the main reason for the office of vice president.
If the president dies then the vice president takes office as president.
Inauguaration
The Vice President.
The outgoing President's term ends at noon, and the President-Elect automatically becomes President at the same time regardless of whether or not he's taken the oath of office. HOWEVER, he cannot act as President, or in effect "execute the office of President of the United States" until he's taken the oath. For example, the Vice-President normally takes his oath before the President. Assuming the VP's been sworn in a few moments before noon, he would constitutionally be "Acting President" until the President takes his oath.