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.”

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.

The program — known as Pepfar, for President’s Emergency Plan for AIDS Relief — seeks to treat 11.4 million infected people by the end of 2016 and 12.9 million by the end of 2017. But even if it met its goals, the program would not be large enough to treat all those who need help.

The United States has for decades been the world’s largest contributor to international development efforts, and the Obama administration has undertaken a variety of new programs, like Power Africa, which is supposed to bring electricity to some of the most impoverished parts of the planet. The program has yet to show much success since Mr. Obama introduced it in South Africa in 2013.

For Mr. Obama, a more perilous part of the 70th annual United NationsGeneral Assembly will begin on Monday, when he is to meet with President Vladimir V. Putin of Russia to discuss Russia’s recent military buildup in Syria.

But eradicating poverty, particularly in Africa, has been a focus throughout Mr. Obama’s presidency, and administration officials said that his speech on Sunday, at the end of a three-day summit meeting on development, would be valuable even without great new American commitments.

Mr. Obama promised the gathering of world leaders that, having given six such previous speeches, he would be blunt. He proceeded to list what he saw as the major stumbling blocks to ending poverty, including corruption, inequality, sexism, war and climate change.

“One of the best indicators of whether a country will succeed is how it treats its women,” Mr. Obama said, then continued, “And I have to say I do not have patience for the excuse of, ‘Well, we have our own ways of doing things.’ ”

Mr. Obama paused and added: “We understand that there is a long tradition in every society of discriminating against women. But that’s not an excuse.”

The speech came near the conclusion of a United Nations effort to adopt a spectacularly ambitious set of global development goals, meant to save the planet and its most vulnerable people. Known as the Sustainable Development Goals — or Agenda 2030, after the deadline for meeting them — they were adopted on Friday at the opening of the summit meeting.

The goals focus on attacking the misery and death associated with poverty with the same intensity and commitment devoted to the global H.I.V.-AIDS epidemic and to the Ebola outbreak that began last year in West Africa. About 162 million children around the world are considered malnourished and likely to have lifelong intellectual and physical deficits.

The stubborn continuation of childhood hunger and death led the assembled leaders to adopt a comprehensive set of 17 goals and to designate 169 specific targets for action in hopes that wide-ranging improvements would yield greater advances than simple growth in income has so far achieved. In the previous round of targets, the number of people living in dire poverty around the world was cut in half largely because of economic growth in China and India, but the goal of reducing child mortality by two-thirds was missed.

An important reason may be that many of the world’s stunted and emaciated children — particularly those in India — suffer less from a lack of food than from a lack of clean water and a sanitary environment. Many stunted children seem too sick to absorb nutrients even when they get enough food. Having a toilet at home, particularly in a densely populated area, may be particularly crucial. But building toilets and water and sewage systems is far more expensive than providing food.

Indeed, the estimated price for achieving the goals adopted by the conclave is $3 trillion.

But figuring out how to measure whether countries are meeting their targets remains a sticky subject.

For sanitation, one measure has long been the number of toilets built. But in India, most toilets built by the government are soon abandoned by their recipients. And even when sewage makes it into toilets there, most of the resulting effluent is dumped untreated into rivers and streams. The country’s sanitation problems are leading to a huge increase in the development of multidrug-resistant bacteria that are spreading around the world.