Formal duty of the vice president?

The Vice President of the United States (sometimes referred to as VPOTUS, Veep, or VP) is the first person in the presidential line of succession, becoming the new President of the United States upon the death, resignation, or removal of the president. As designated by the Constitution of the United States, the vice president also serves as the President of the Senate, and may break tie votes in that chamber. He or she may be assigned additional duties by the President