UNITED NATIONS — President Bush tried to assure world leaders on Tuesday that he is acting decisively and quickly to contain a U.S. financial crisis that is going global.

"I know that many of you here are watching how the United States government will address the problems in our financial system," he said in a speech to the annual U.N. General Assembly. "In recent weeks we have taken bold steps to prevent a severe disruption of the American economy, which would have a devastating effect on other economies around the world."

The mention of the economic turmoil came near the end of a 20-minute speech before a roomful of leaders from around the globe.

He said that his administration is working with Congress to come to fast agreement on a $700 billion bailout bill, in addition to other recent actions it has taken that he called "bold steps" aimed at stabilizing markets and keeping credit flowing. The president told them he is confident that the U.S. will act "in the urgent timeframe required" to prevent broader problems.

Bush did not ask for any action by other countries.

The rescue plan proposed by the Bush administration and before Congress for approval would allow the U.S. government to buy bad mortgages and other troubled assets from financial institutions, in the hopes of easing the choking credit crunch that has thundered from Wall Street to Main Street and across the world.

Bush also addressed the global view of the U.S. problems earlier Tuesday, during a meeting at New York's Waldorf Astoria Hotel with Pakistan's new president, Ali Zardari. He said that he had begun selling the plan to world leaders Monday night upon his arrival in New York for three days of international meetings.

He said he has been telling fellow leaders that the proposal devised by Treasury Secretary Henry Paulson "is a robust plan to deal with a serious problem," but that he knows those leaders are skeptical about Congress.

"I've assured them as well, having spoken to the leaders of Congress of both political parties, that there is the desire to get something done quickly," Bush said.

The president took note of Democrats' hopes to change the bill with provisions to limit the pay of top executives whose firms need help, provide more help for unemployed workers and reduce mortgage payments for borrowers facing foreclosure, among other things.

"There are good ideas that need to be listened to in order to get a good bill out that will address the situation to get this piece of legislation passed which is necessary to address the financial situation and provide a rescue plan to make sure that there's stability in the markets," he said.

White House spokesman Tony Fratto told reporters flatly that not passing legislation this week would be "unthinkable."

It's not just about saving Wall Street businesses or about keeping credit flowing so that Main Street companies can expand and create jobs, he said. It's also about merely maintaining the jobs that exist now across the whole economy, Fratto said.

"Every business, every employer — and so every employee in America — depends every day on the flow of money through our financial system to sustain their normal business operations," Fratto said. "That includes financing payrolls, maintaining their inventories — these are Main Street businesses that rely on a functioning banking system."

Fratto defended the administration against the charge that lawmakers are being asked to act too quickly on a giant package that they have had only days to learn about and question.

"I'll concede that it's a lot of information to take in in a relatively short period of time," Fratto said. "But I think they can — I think it's enough time."

Vice President Dick Cheney, White House chief of staff Josh Bolten and Keith Hennessey, the director of the president's economic council, were spending Tuesday on Capitol Hill lobbying on the president's behalf. They met Tuesday morning with conservative lawmakers from Bush's party who oppose the bailout.

Fratto would not comment on lawmakers' ideas on capping executive pay or other provisions in debate. He did say the White House understands and accepts the congressional demands for "robust" transparency and oversight.

"We're asking the American taxpayer to essentially front an investment here," he said.