WASHINGTON — House Speaker Nancy Pelosi pressed top congressional Democrats on Wednesday to pass a massive economic recovery bill by mid-February, a call tempered by new projections of unprecedented deficits ahead.

Pelosi emphasized the infrastructure and energy components of a massive stimulus package that Congress and President-elect Barack Obama are fashioning in response to the worst economic downturn since the Great Depression. The combined spending and tax cuts of the plan are expected to cost nearly $800 billion.

"Many will focus on the cost of it," Pelosi told the House Democratic Steering and Policy Committee. "While we are not discussing small sums, the bill is fiscally responsible because it will provide a fiscal dividend by returning 40 percent of the cost to the Treasury — at least that much in increased revenue."

Noting that the proposal will include spending on roads and bridges, clean energy technologies, expanded Internet access, and modernizing schools, she declared: "This is not your grandfather's public works bill."

Pelosi's call for passage by mid-February represents a slight adjustment in the Democrats' anticipated schedule for the legislation. Just on Monday, Obama had said he hoped for passage at the end of January or the first week in February.

Pelosi's exhortation came as Obama was offering a promise of long-term fiscal discipline as a salve to the huge two-year expenditure in the planned recovery plan. Budget-conscious lawmakers are pressing Obama to embrace deficit-reduction goals — a task made all the more stark Wednesday with a new Congressional Budget Office prediction that the deficit would reach an unprecedented deficit of $1.2 trillion for the 2009 budget year.

"Part of the discussion that needs to happen right now is not what we do just right now, but what we look to in the future — about how we get back to a balanced budget and then start to deal with this horrible, horrible national debt that we have," said Rep. Dennis Moore of Kansas, a member of the congressional Blue Dogs, a coalition of conservative and moderate Democrats.

Two weeks away from assuming the presidency, Obama vowed Tuesday to "bring a long-overdue sense of responsibility and accountability to Washington" and called the need for budget reform "an absolute necessity."

On Wednesday, he named Nancy Killefer as his chief performance officer, a White House official who will work with federal agencies to set performance standards and hold agency managers accountable for progress. Killefer is director of a management consulting firm and served as an assistant secretary of the Treasury under President Bill Clinton.

"The fact that he is making these comments publicly about fiscal responsibility gives me encouragement that we will see something," said Rep. Charlie Melancon of Louisiana, one of the leaders of the Blue Dog Coalition.