The Charter of Paris for a New Europe was adopted by a summit meeting of most European governments in addition to those of Canada, the United States and the Soviet Union, in Paris from 19–21 November 1990. The charter was established on the foundation of the Helsinki Accords and was further amended in the 1999 Charter for European Security. Together, these documents form the agreed basis for the Organization for Security and Co-operation in Europe. However, not all OSCE member countries have signed the treaty.