United States President Barack Obama addresses the conclusion of the 10th plenary meeting of the High-level plenary meeting of the United Nations summit for the adoption of the post-2015 development agenda

UNITED NATIONS — President Obama told a conclave of world leaders here on Sunday that millions of people should be saved through collective action to end extreme poverty and deadly infections, but he did not announce new initiatives to achieve those ends.

“Billions of our fellow human beings are at risk of dying from diseases that we know how to prevent,” Mr. Obama said. “Many children are just one mosquito bite away from death. And that is a moral outrage.”

One of the best indicators of whether a country will succeed is how it treats its women.

Mr. Obama did announce a modest expansion of a program that provides drugs to those infected with H.I.V., mostly in Africa. But increasing the number of people receiving treatment may require more funding from Congress, and with a possible government shutdown looming amid congressional disputes over spending, the additional money is uncertain.