(b) The source or special fissile material subject to the safeguard measures provided for in this Agreement shall be the material in those facilities that has been identified by the Agency at a given time in accordance with Article 2(b). On December 2, 1967, President Johnson stated that the United States has not asked a country to accept security measures that the United States does not want to accept and that “if such safeguard measures are applied within the framework of the treaty, the United States will authorize the International Atomic Energy Agency to apply its security measures to all nuclear activities in the United States, with the exception of those with a direct sense of national security. The United Kingdom announced a similar offer on 4 December 1967. These two offers have contributed significantly to the acceptance of the NPT in the major industrialized countries and their importance has been emphasized in the public statements of the Federal Republic of Germany, Japan and others. The US offer would be bounded by a separate formal agreement with the IAEA. In March 1971, the Safeguard Committee concluded its elaboration of detailed provisions for each guarantee agreement. The Council approved the document and, shortly thereafter, Austria and Finland negotiated safeguards agreements with the IAEA, which became a model for future agreements known as comprehensive security and security agreements. They have also been used with significant modifications in the development of guarantee agreements, known as voluntary offer agreements, with the United States and the United Kingdom, then with Russia, France and China.