Addressing the UN General Assembly, he also said multilateral financial institutions should give developing countries an enhanced voice in their decision-making structures.
India has been campaigning for its inclusion in an expanded and restructured Security Council, a move that has been backed some key P-5 members though China has been non-committal.
"For multilateralism to remain relevant and effective in the future, multilateral institutions need to be reformed. The place to begin is right here," Singh said.
Multilateral efforts must guide the quest for peace and security wherever they are threatened, Singh said. "And the centrality and contribution of the UN system to development must be restored," Singh said.
"These objectives require the building of a new international consensus, suited to our time and rooted in today's realities. It is only such a plan of action that will enable the UN to meet the twin tests of legitimacy and efficacy," he added.