In general, the financing for the implementation of Agenda 21 would come from a country's own public and private sectors. For developing countries, particularly the least developed countries, overseas development aid (ODA) is a main source of external funding, and substantial new and additional funding for sustainable development and implementation of Agenda 21 would be required. Developed countries reaffirmed their commitment to reach the accepted United Nations target of 0.7% of GNP for ODA and, to the extent that they had not yet achieved that target, agreed to augment their aid programmes in order to reach that target as soon as possible and to ensure prompt and effective implementation of Agenda 21. Some countries agreed to reach the target by the year 2000. It was decided that the Commission on Sustainable Development would regularly review and monitor progress towards this target. Those countries that had already reached the target should be encouraged to continue contributing to the common effort to make available the substantial additional resources that had to be mobilized. Other developed countries, in line with their support for reform efforts in developing countries, agreed to make their best efforts to increase their level of ODA. In this context, the importance of equitable burden-sharing among developed countries was recognized. Other countries, including those undergoing the process of transition to a market economy, might voluntarily augment the contributions of the developed countries.
This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the UN Commission on Sustainable Development and implemented through national and local authorities. Agenda 21 indicates that the review process should systematically combine the monitoring of the implementation of Agenda 21 with a review of the financial resources available.