House Democrats and Republicans failed to reach a deal on an economic stimulus package Wednesday, but both sides vowed to keep working on a bipartisan approach that could be enacted quickly.

Disagreement within the House Democratic Caucus over whether to apply pay-go budget rules and GOP calls for the package to include an extension of the controversial Bush tax cuts, however, loomed as serious threats to the legislation.

Pelosi struck a conciliatory note after the meeting, saying Boehner had offered some “constructive” ideas.

“I’m optimistic that we can go forward in this matter, and hope that it can be done in a way that is timely, that is targeted and that is temporary,” she said in a statement.

Boehner acknowledged there was no agreement but said Republicans would continue to work with Democrats on a package “that truly is stimulative – not for the federal government, but for our nation’s increasingly sluggish economy.”

After the meeting with Pelosi, Boehner quipped “there would be no problems.”

But Democrats such as Sen. Charles Schumer (D-N.Y.) said potential Republican insistence on tax cuts remained “the number one obstacle” to the bill. “That will derail it as sure as we are here,” Schumer said during a press conference.

Key House Democrats also said any deal would hinge on President Bush, who may unveil proposals to stimulate the economy next week.

“Basically, what we do is going to be determined by what the administration  agrees to do or not do,” House Ways and Means Chairman Charles Rangel (D-N.Y.) said.

Democrats emphasized Wednesday that the package could and should be passed quickly, with Hoyer saying work should be completed within a month.

 “I believe it can be done in 30 days,” Hoyer told reporters. “Whether it will be done in 30 days, I can’t say.”

Schumer also emphasized that the package should be completed quickly. “We’d like to do this as soon as possible. If this isn’t done by the [end of the] first quarter … it may be too late,” said Schumer, the chairman of the Joint Economic Committee, which includes lawmakers from both chambers.

He said he had discussed the need for a package with Federal Reserve Chairman Ben Bernanke, who Schumer said emphasized the need to act quickly.

Schumer said that the package would cost roughly $100 billion and likely would have middle-class tax cuts and spending increases for unemployment benefits and food stamps as its centerpiece. He said some business tax cuts were “on the table” in order to attract Republican support.

He warned his colleagues to resist attempting to attach more divisive or complex measures, saying this could slow or imperil the legislation. “If this becomes the vehicle for everyone’s particular agenda, then I think this process becomes that much more complicated.”

The New York Democrat echoed comments made by other key Democrats that the pay-go rules should be waived to avoid dampening the effect of any relief. “There’s not unanimity, but a growing consensus that this is not the time for pay-go.”

For Democrats, another challenge could come from conservative members of their own caucus who do not want pay-go to be waived for the stimulus package. Key Democrats, including Schumer, House Majority Whip James Clyburn (D-S.C.) and presidential candidates Sens. Hillary Rodham Clinton (N.Y.) and Barack Obama (Ill.) have signaled support for waiving pay-go.

Rep. Allen Boyd (D-Fla.), a leader of the Blue Dogs, said the conservative group would oppose waiving the rule. “We want it fully offset,” he said.

However, Boyd said members were mulling whether they could accept a package if the costs were paid for later in the five-year budget window. This would avoid violating pay-go.

While Democratic leaders for the most part emphasized bipartisanship in their public comments, Hoyer blamed President Bush’s economic policies for causing the current slowdown and said President Clinton’s economic policies brought prosperity. “People were much better off eight years ago than they are today,” Hoyer told reporters. “I’ve been here 27 years and I don’t think the economic policies of Republicans have worked.”

Jackie Kucinich contributed to this article