>>5198510 (lb)
The power of the President to refuse to approve a bill or joint resolution and thus prevent its enactment into law is the veto. … This veto can be overridden only by a two-thirds vote in both the Senate and the House. If this occurs, the bill becomes law over the President's objections.
Sauce:
https://www.senate.gov/reference/reference_index_subjects/Vetoes_vrd.htm