Lawmakers pressed ahead Tuesday with plans to kickstart the ailing U.S. economy, as the Federal Reserve Board stepped in with a big interest rate cut aimed at spurring growth and stabilizing a battered stock market.

House Speaker Nancy Pelosi , D-Calif., Senate Majority Leader Harry Reid , D-Nev., and other leaders from both parties were to meet with President Bush at the White House to discuss a stimulus package, following up on a conference call last week.

The Fed meanwhile lowered a key interest rate by three-quarters of a percentage point, to 3.5 percent, halting a huge stock market drop on Wall Street that had followed yesterday’s selloff in world financial markets.

Senate Finance Committee Chairman Max Baucus , D-Mont., said Congress must keep working on a fiscal stimulus plan.

“Will monetary stimulus be enough?” Baucus asked. “There are reasons to believe that it might not.”

Bush and congressional leaders of both parties are seeking ways to pump up the U.S. economy, which has been battered by the subprime mortgage mess, a housing slump and a credit crunch.

“Whether it’s herd mentality or restructuring of the markets, world markets are reacting to the situation in America,’’ Pelosi said after congressional leaders met at midday with Treasury Secretary Henry M. Paulson Jr. , the president’s point man on a stimulus package.

Bush on Jan. 18 called for individual income tax rebates and investment incentives for business equal to about 1 percent of the $14-trillion-plus gross domestic product. The White House might be open to an even bigger package, press secretary Dana Perino suggested.

Reid said Congress needs to pass a stimulus package by the President’s Day recess, which begins Feb. 16. “It’s not easy, but we’re going to have to get it done as quickly as possible.”