WASHINGTON — President Bush and two Democratic leaders in the Senate tried to assure Americans on Friday morning that lawmakers and the administration would be able to come together and reach an agreement on a proposal to rescue the country’s financial system.

We are going to get a package passed,” Mr. Bush said, a day after an earlier agreement dissolved amid a flurry of political rancor. “We will rise to the occasion. Republicans and Democrats will come together and pass a substantial rescue plan.”

Bush delivered a terse statement from outside the Oval Office of the White House, acknowledging lawmakers have a right to express their doubts and work through disagreements on the $700 billion plan, but declaring they must work to avert an economic meltdown.

"There are disagreements over aspects of the rescue plan," he said, "but there is no disagreement that something substantial must be done. We are going to get a package passed."

GOP Presidential nominee John McCain, who had said he was suspending his campaign to forge a bipartisan agreement, reversed course and planned to attend the previously scheduled debate Friday night with Democratic rival Barack Obama.

A short time later, the Senate majority leader, Harry Reid of Nevada, made similar assurances. “We’re going to get this done and stay in session for as long as it takes to get it done,” Mr. Reid said.

The pledges came as lawmakers and administration officials were gearing up for a second day of discussions about the shape of the $700 billion rescue package. Thursday’s agreement, which seemed like a sure thing by early afternoon, fell apart during a meeting later in the day at the White House after House Republicans rejected the proposal brokered by the Treasury secretary Henry M. Paulson Jr.

Speaking from the White House, President Bush noted the disagreements among lawmakers about how the rescue should be shaped. “There are disagreements over aspects of the plan,” Mr. Bush said, “but there is no disagreement that something substantial must be done,” he said.

While noting that progress had been made in reaching an agreement, Mr. Reid, standing next to Senator Christopher J. Dodd, Democrat of Connecticut and chairman of the Senate banking committee, criticized House Republicans as well as the Republican presidential candidate, John McCain, who suspended his campaign amid promises to come to Washington and help hammer out a deal.

Mr. Smith, the aide to Mr. Boehner, said the leader had directed a group of Republicans a few days ago to see whether they could come up with alternatives that relied less on tax funds in providing the rescue package; that led to Mr. Cantor’s mortgage-insurance approach. He said Mr. Boehner thought Mr. Cantor’s idea should be taken into consideration in the talks.

The House Republicans’ revolt shocked Democrats; Mr. Reid said later that he was under the impression that Mr. Boehner had been a strong advocate for moving forward with the Paulson plan.

Mr. Frank, the Massachusetts Democrat, who attended the White House meeting, was shocked as well. “We were ready to make a deal,” Mr. Frank said later.

Ms. Pelosi told reporters that she was open to considering ideas proposed by the House Republicans. And Mr. McCain and Mr. Obama both said they held out hope that a deal could be reached soon.