Government of the United Kingdom
26 July 1968
The Government of Mexico understands:
1. that, in accordance with what is laid down in Article VII of the Treaty, none of the provisions of the said Treaty shall be interpreted as affecting in any way whatsoever the rights and obligations of Mexico as a State Party to the Treaty for the Prohibition of Nuclear Weapons in Latin America (Treaty of Tlatelolco), opened for signature on 14 February, 1967, and concerning which the United Nations General Assembly adopted Resolution 2286 (XXII) of 5 December, 1967;
2. that at the present time any nuclear explosive (device) is capable of being used as a nuclear weapon and that there is no indication that in the near future it will be possible to manufacture nuclear explosives (devices) which are not potentially nuclear weapons. However, if technological advances succeeded in modifying this situation, it would be necessary to amend the relevant provisions of the Treaty in accordance with the procedure established therein.