Law enforcement officers watch the crowd outside a rally in Pittsburgh on Wednesday. The two-day Group of 20 summit starts today. Leaders from nearly two dozen nations are expected to attend the event hosted by President Barack Obama.

PITTSBURGH — With the world's major economies having stepped back from the brink of a devastating meltdown, President Barack Obama comes to a global summit here pushing a slimmed-down agenda designed to prevent a repeat of the conditions that caused such panic a few months ago.

Obama will tell world leaders that the global economy cannot continually rely on huge borrowing and spending by Americans and massive exports by countries such as China.

In informal chats and fancy receptions at the two-day summit beginning today, the buzz words will be "balanced and sustainable."

Obama gave a hint of the message when he spoke at the United Nations in New York on Wednesday. He said other nations cannot "stand by and wait for America to solve the world's problems alone. Now is the time for all of us to take our share of responsibility for a global response to global challenges."

This is the third meeting of the Group of 20 top economies in the aftermath of the financial crisis that plunged the world into fear a year ago. When the G-20 met in April, the economies of the United States and many other countries were under severe strain, and world leaders largely agreed on common remedies such as dramatically increased government spending to provide some stimulus.

Now, with the crisis seemingly averted, the leaders will meet in a calmer atmosphere to discuss how best to keep reinvigorating their economies without repeating earlier mistakes.

"This is not a trillion-dollar summit," said Mike Froman, a top economic adviser to Obama. He told reporters the administration hopes world leaders will agree "on a framework for balanced and sustainable growth, a set of policies, parameters and process" that can "avoid the sort of imbalances that contributed to this crisis."

U.S. officials expect no binding, treaty-like language. But Froman said they hope for some type of process "for holding each other accountable, reviewing each other's actions in much the same way that the G-7 has done in the past in terms of focusing on each other's economic policy frameworks."

Obama plans no one-on-one meetings with world leaders or extensive discussions of Iran, White House officials said late Wednesday. And Froman told reporters that "we do not expect major announcements of new, significant financial commitments."In that regard, the G-20 is likely to have less pizazz than did Obama's visit to the United Nations this week.Still, it will let him play host to an array of world leaders and their spouses and try to nudge them closer to his thinking on climate control, banking regulations and other matters.Obama and his wife, Michelle, will greet their guests at a "working dinner" today at Pittsburgh's Phipps Conservatory and Botanical Gardens.Friday will feature group sessions on various topics, capped by an Obama news conference.The president has signaled plans to call for an end to extensive government subsidies that encourage the use of fossil fuels, such as oil, coal and natural gas, which are believed to contribute to global warming. He will propose a gradual elimination, White House officials said.Many countries, including the U.S., provide tax breaks and direct payments to help produce and use oil, coal, natural gas and other fuels that emit carbon dioxide, a gas that traps heat in the atmosphere.Fast-growing industrial nations such as China and India are likely to resist the idea.G-20 leaders also will discuss limits on bankers' pay in hopes of discouraging risky ventures. And the United States will support greater influence in the International Monetary Fund by emerging economies such as China, India and Brazil. Some European governments complain that the move would come at their expense.

Members of the environmental group Greenpeace dangle with a banner Wednesday from the side of the West End Bridge over the Ohio River in Pittsburgh. Police said eight of the nine people were arrested and charged with various misdemeanors. A ninth person is being charged with conspiracy. Greenpeace is urging action from President Barack Obama and the other leaders coming to the city for the Group of 20 summit.