A/RES/59/250 10. Stresses that the purpose of reform is to make the United Nations development system more efficient and effective in its support to developing countries to achieve the internationally agreed development goals, on the basis of their national development strategies, and stresses also that reform efforts should enhance organizational efficiency and achieve concrete development results; 11. Requests the organizations of the United Nations system to continue their efforts to respond to national development plans, policies and priorities, which constitute the only viable frame of reference for programming their operational activities at the country level, and to pursue full integration of the operational activities for development at the country-level with national planning and programming, under the leadership of national Governments, at all stages of the process, while ensuring the full involvement of all relevant stakeholders at the national level; 12. Welcomes the efforts of the Secretary-General, through the members of the United Nations Development Group and the United Nations System Chief Executives Board for Coordination, as appropriate, to enhance the coherence, effectiveness and efficiency of the United Nations development system at the country level; 13. Recognizes that strengthening the role and capacity of the United Nations development system to assist countries in achieving their development goals requires continuing improvement in its effectiveness, efficiency, coherence and impact, along with a significant increase in resources and an expansion of its resource base on a continuous, more predictable and assured basis; II Funding for operational activities for development of the United Nations system 14. Emphasizes that increasing financial contributions to the United Nations development system is key to achieving the MDGs,2 and in this regard recognizes the mutually reinforcing links between increased effectiveness, efficiency and coherence of the United Nations development system, achieving concrete results in assisting developing countries to eradicate poverty and achieve sustained economic growth and sustainable development through operational activities for development and the overall resourcing of the United Nations development system; 15. Emphasizes also that funding of operational activities for development of the United Nations system should focus on long-term development challenges based on national development strategies; 16. Notes with concern that the United Nations development system has not benefited commensurately from recent increases in official development assistance, despite the additional tasks entrusted to the United Nations system in the implementation of and follow-up to internationally agreed goals; 17. Stresses that core resources, because of their untied nature, continue to be the bedrock of the operational activities for development of the United Nations system, and in this regard notes with appreciation that core contributions to United Nations funds and programmes have begun to increase again over the last three years; 18. Calls upon donor countries and other countries in a position to do so to substantially increase their contributions to the core/regular budgets of the United 4