At the end of the negotiations, the contract will be signed by representatives of the governments concerned. The conditions may require ratification and signature of the treaty before it becomes legally binding. A government ratifies a treaty by depositing an instrument of ratification in a place defined by the Treaty; The instrument of ratification is a document containing a formal confirmation of the Government`s approval of the provisions of the Treaty. The ratification process varies according to the laws and constitutions of each country. In the United States, the president can only ratify a treaty after receiving the “advice and approval” of two-thirds of the Senate. Formally, the opportunity, if a country formally joins a group of countries or accepts an agreement between countries, not to test nuclear weapons In addition to treaties, there are other less formal international agreements.