The Constitution gives the Senate the power to approve for ratification, by a two-thirds vote, treaties negotiated by the president and the executive branch. The Senate has rejected relatively few of the hundreds of treaties it has considered since 1789, although many have died in committee or been withdrawn by the president. Prior to approval, the Senate may amend or adopt changes to a treaty. In some cases, the president enters into executive agreements with foreign nations, often for regulation of trade, and such agreements are not subject to Senate approval.
More about Treaties.
