Finally, mention must be made of various links with secular organizations working for the promotion of justice, peace and the respect for human dignity. Over the years, relations with international organizations have increased considerably. Because of the interest of the Holy See in the work of the United Nations, the Pontifical Council, in collaboration with the Secretariat of State, has frequent contacts with the United Nations and its specialized agencies, especially at the time of the major international conferences that deal with such questions as development, population, environment, international trade, or human rights. Equal importance is given to regional organizations, among which the Council of Europe and the European Union. The Pontifical Council also welcomes exchanges with non-governmental organizations that share its aims and are working in the field of peace, justice and human rights.