In many ways, the task this year will be even tougher than it was five years ago, when the Millennium Development Goals were adopted. Instead of just setting targets, this time leaders must decide on concrete steps to achieve them. They must agree on a plan to reach the Goals.
The agenda for our New York summit in September is even larger than that. It is based on the understanding that development, security and human rights are not only ends in themselves - they reinforce each other, and depend on each other. In our interconnected world, the human family will not enjoy development without security, it will not enjoy security without development, and it will not enjoy either without respect for human rights. To act on that understanding, we also need to reinvigorate the United Nations itself.
The issues on the table are of vital importance to every human being on the planet. If the summit takes decisions that help to strengthen our collective security; if we make real progress in our fight against poverty, disease and illiteracy; if the world provides the means to reach all the Millennium Development Goals; if governments recognise the centrality of human rights, and reform the United Nations to ensure it is up to the job it has to do - then all the world's people will benefit.
We have a once-in-a-generation chance to bring about historic, fundamental change. But it will depend on the will of governments, and on the commitment of groups and individuals such as you. So between now and September, please keep making your voices heard loud and clear enough to lift the sky. And keep raising your voices after that, to hold governments to their promises, and to help translate those promises into action.
Let history not say about our age that we were those who were rich in means but poor in will. Let it say that "we who were strong in love", as Wordsworth put it, were the ones who really did make poverty history.