U.S. President Barack Obama says the last-minute compromise deal to raise the country’s borrowing limit and cut spending averted a possible “disastrous blow” to the United States economy.

But Mr. Obama said Wednesday before a Cabinet meeting it will be “challenging work” for Congress to find additional ways to lower the country’s deficit, as required by the agreement.

Mr. Obama has previously said everything will be on the table for the commission, including social safety net programs such as Social Security and Medicare, which some Democrats say are untouchable. He also warns that there can be no more debt reduction without eliminating tax breaks for corporations and the wealthy — something many Republicans oppose.

The debt deal he signed Tuesday allows the government to continue borrowing money through 2012 in exchange for spending cuts of almost $1 trillion over the next 10 years. The package also creates a bipartisan budget committee that will seek up to another $1.5 trillion in deficit reduction. If the panel fails to reach an agreement, then the deal would trigger stiff, automatic spending cuts.

U.S. Treasury Secretary Timothy Geithner defended the compromise deal Wednesday, saying it gives government officials a chance to fix a broken system.

Writing in the Washington Post, Geithner said the last-minute debt deal takes away the threat of a default, which could cause interest rates to rise and force consumers to pay more for credit cards and other needed loans.

He says the deal will allow the government to make investments in education, technology and infrastructure that could help the economy grow.

The agreement also has some prominent critics.

The chief executive of one of the world’s biggest investment firms said Wednesday the deal “darkens an already fragile outlook” for the U.S. economy. Writing in the Financial Times, Pimco’s Mohamed El-Erian warns the deal does little to reduce the country’s actual deficits and postpones decisions on key issues.

The major credit rating agencies are also being cautious.

Moody’s Investor Services said late Tuesday it will maintain the United States government’s top AAA rating, but warns the outlook for the country is negative. Fitch Ratings said the risk of the U.S. defaulting on its debts remains extremely low but added it wants to see a credible plan to further reduce the U.S. budget deficit.