When U. S. Presidents propose a federal budget, sign a bill into law, or veto a bill, which role are they fulfilling?

executive role

Explanation:

Remember, the U.S. President falls under the executive arm of government. Furthermore, according to Article II of the U.S Constitution, U.S Presidents have formal executive powers to propose a federal budget, sign a bill into law, or veto a bill.

For example, when the U.S President veto ( refuse to approve) a bill, he would be acting under the power granted to him as an executive.