WASHINGTON -- Piling cuts on top of cuts, House Republican leaders outlined an additional $26 billion in spending reductions Thursday in hopes of placating conservatives who rejected an initial draft as too timid.

Rep. Harold Rogers, R-Ky., in charge of drafting the legislation, said he had proposed "deep but manageable cuts in nearly every area of government."

No details were immediately available, but the move would cut current spending in hundreds of federal programs by about $60 billion, resulting in levels in effect in 2008.

By Republican reckoning, the new measure would reduce spending by $100 billion below President Barack Obama's request for the current fiscal year, a number they had promised to meet in the "Pledge to America," their manifesto in the 2010 campaign. The actual cuts from current rates are less because the $100 billion promise assumes Obama budget increases that were never enacted.

Rogers had warned Wednesday that such cuts could lead to layoffs of FBI agents and harm to the nation's air traffic control system. He also warned of cuts to health research, special education and Pell Grants for low-income college students.

Thursday's announcement caps a long struggle among Republicans over what they meant exactly when promising to cut $100 billion last year in their Pledge to America. At the center of the debate has been the fact that the budget year began Oct. 1 and the government has been spending money at last year's levels since then. A stopgap government funding bill expires March 4.

That makes it much harder to keep the promise because it squeezes a year's worth of cuts into seven months. House Speaker John Boehner, R-Ohio, had earlier promised to spread the cuts over a calendar year, with the upcoming spending bill making a significant down payment in advance of another round of cuts as Congress hashes out next year's appropriations bills.

But rank-and-file Republicans, many of whom have little hands-on knowledge of the budget and the impact the cuts will have on programs popular with their constituents, insisted on keeping the $100 billion promise, forcing Boehner and the appropriations panel to go back to the drawing board.

"It's important to do what we said we were going to do," said Rep. Jeff Flake, R-Ariz.

Boehner met with GOP freshmen Thursday afternoon to sell the plan, which Republicans expect to unveil this afternoon.