This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities. Agenda 21 recommends that the UN regional economic commissions should play a leading role in coordinating regional and sub-regional activities by sectoral and other UN bodies and should assist countries in achieving sustainable development. These commissions, regional programmes within the UN system, as well as other regional organizations should review the need for modification of ongoing activities in the light of Agenda 21.