The President of the United States can respond to a bill in the following ways:
Sign the bill into law.
Veto the bill, returning it to Congress with his objections.
Do nothing, in which case the bill becomes law without the President's signature after 10 days (excluding Sundays).
The President cannot:
Amend the bill.
Rewrite the bill.
Ignore the bill.
If the President vetoes a bill, Congress can override the veto with a two-thirds majority vote in both the House of Representatives and the Senate. If the President does nothing, the bill becomes law without his signature after 10 days (excluding Sundays).