A/RES/55/183 (b) In the context of the process of trade liberalization, tariff peaks should be minimized and the use of trade-distorting policies and protectionist practices and non-tariff barriers should be eliminated as they have negative effects on the ability of developing countries to diversify their exports and undertake the required restructuring of their commodity sector and have an adverse impact on liberalization measures taken by commodity-dependent developing countries and their efforts to eliminate poverty; (c) In line with Agenda 21 7 and the Rio Declaration on Environment and Development, 8 Governments should make it their objective to ensure that trade and environmental policies are mutually supportive so as to achieve sustainable development; in so doing, their environmental policies and measures with a potential trade impact should not be used for protectionist purposes; (d) In the light of the process of multilateral trade liberalization, which has led to the diminution of differentials accorded by preferred trade regimes, there is a need to take measures, as appropriate and consistent with international obligations, to address the diminution, in particular by strengthening technical assistance, by continuing to provide financial assistance to commodity-dependent developing countries and by addressing supply-side constraints faced by such countries, in order to improve the competitiveness of their commodity sectors and to overcome difficulties encountered in their diversification programmes; (e) Timely and effective financial cooperation to facilitate the management by commodity-dependent countries of excessive fluctuations in commodity export earnings should be maintained and further pursued; (f) Strengthening technical cooperation in the areas of transfer of new technologies and know-how in production processes and training for technical, managerial and commercial staff in developing countries is of paramount importance for quality improvements in the commodity sector; (g) Expansion of South-South trade and investment in commodities enhances complementarities and offers opportunities for intersectoral linkages within and among exporting countries; (h) There is a need to promote, expand and intensify research and development, to provide infrastructure and support services and to encourage investment, including joint ventures in developing countries engaged in the commodity and commodity-processing sectors; 7. Encourages the Common Fund for Commodities, in cooperation with the International Trade Centre, the United Nations Conference on Trade and Development and other relevant bodies, to continue to expand the activities of its Second Account with the necessary and effective support for research and development and extension services in developing countries, including adaptive research on production and processing aimed at smallholders and small-sized and medium-sized enterprises in developing countries, in order to widen the scope of activities and thus ensure the effective participation of all stakeholders; 7 Report of the United Nations Conference on Environment and Development, Rio de Janeiro, 3-14 June 1992 (United Nations publication, Sales No. E.93.I.8 and corrigenda), vol. I: Resolutions adopted by the Conference, resolution I, annex II. 8 Ibid., annex I. 3