With fresh evidence that the U.S. economy is shedding jobs even faster than expected, President-elect Obama said Friday that his top concern is passage of a multibillion-dollar stimulus package to create jobs.

In his first press conference since winning the presidency, Obama said he would tackle the nation's financial crisis "head on."

"Some of the choices that we make are going to be difficult," he said, reading a statement before taking several questions. "It is not going to be easy for us to dig ourselves out of the hole that we are in. But America is a strong and resilient country."

Obama urged Congress to pass an economic stimulus measure and extend unemployment benefits either before or just after he takes office.

As for bigger decisions, he said, the nation has "only one government and one president at a time," and now it is President Bush.

However, he said, "immediately after I become president, I will confront this economic crisis head-on by taking all necessary steps to ease the credit crisis, help hardworking families, and restore growth and prosperity."

"I'm confident a new president can have an enormous impact," he said.

Obama said he would focus on producing jobs, and he mentioned actions to help the auto industry, small businesses and state and local governments.

He left open the possibility that economic conditions might prompt him to change his tax plan, which would give a break to most families, but raise taxes on those making more than $250,000 annually.

Obama's remarks followed a meeting of his top economic advisers and a spate of dire news on the economy.

"Tens of millions of families are struggling to figure out how to pay the bills and stay in their homes," Obama said, standing before luminaries such as former Treasury Secretary Robert E. Rubin and former Federal Reserve Chairman Paul A. Volcker. "Their stories are an urgent reminder that we are facing the greatest economic challenge of our lifetime, and we're going to have to act swiftly to resolve it."

The president-elect called on members of both parties to "set politics aside for a while" to deal with the economic crisis. Yet politics continued in Washington as congressional Democrats and the White House clashed over the stimulus package and free trade agreements.

The White House signaled Friday that it is likely to oppose stimulus proposals from Democrats, arguing that the ideas mentioned so far would have little immediate impact and that the $700 billion rescue plan approved last month needs more time to play out.

The outlines of the Democrats' stimulus plan are similar to the version the House approved Sept. 26, providing a 13-week extension of unemployment benefits as well as increased funding for food stamps and infrastructure projects, and to states for Medicaid costs. Also on the table is a proposal to double the $25 billion in low-interest loans to automakers to produce more fuel-efficient vehicles.

Speaking to reporters before Obama's press conference, White House spokesman Tony Fratto said the administration would review any legislation, but that the stimulus proposals Democrats floated are "very limited and very forward-looking and long-range," such as large-scale public infrastructure projects that could take years to complete.

Obama's transitional economic team, drawn from a broad swath of academia and finance, convened behind closed doors at the Hilton in Chicago. Members included former Treasury Secretary Lawrence Summers, newly appointed chief of staff Rahm Emanuel, Vice President-elect Joseph Biden, Michigan Gov. Jennifer Granholm and Time Warner Chairman Richard Parsons. Billionaire investor Warren E. Buffett participated via speakerphone.

An Associated Press report is included in this story.