WASHINGTON (AP) One of President Barack Obama's top economic advisers says the nation can afford to spend hundreds of billions of dollars in an attempt to jump-start a weak economy. But Larry Summers warns that fiscal discipline will be necessary once the economy recovers.

He says the government must spend money now to revive an economy that shed more than 2 million jobs last year. An $825 billion package of government spending and tax cuts is working its way through Congress. It would be the largest economic stimulus package ever enacted.

Even without the new proposal, the federal budget deficit is above $1 trillion this year.

Republicans in Congress generally agree that the government must act to improve the economy, but they question the size of the package and they want more of it to go to tax cuts.

Summers spoke on NBC's "Meet the Press."

Copyright 2009 The Associated Press.