CHICAGO - (AP) - President-elect Obama said Friday that the country is facing the greatest economic challenge of our lifetimeand "we're going to have to act swiftly to resolve it."

Click here to view President-elect Obama?s news conference

However in his first news conference since winning thepresidency Tuesday, Obama deferred to President Bush and hiseconomic team, noting that the country has only one government andone president at a time.

He said the Congress needs to pass an economic stimulus measureeither before or just after he takes office in January.

But, he said, "immediately after I become president I willconfront this economic crisis head-on by taking all necessary stepsto ease the credit crisis, help hardworking families, and restoregrowth and prosperity."

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

The president-elect spoke after he and Vice President-elect JoeBiden met privately with economic experts to discuss ways tostabilize the troubled economy.

More evidence of a recession came Friday when the governmentreported that the unemployment rate had jumped from 6.1 percent inSeptember to 6.5 percent in October. Despite dour third-quarterreports from Ford and General Motors, stocks rose some after twodays of heavy losses.

Obama's transition to power and early days in office, if not theentire first year of his presidency, almost certainly will bedevoted to finding ways to remedy dismal economic conditions. Theeconomy was the top concern of voters demanding a new direction asthey ushered into office the Democrat who promised change aftereight years of Bush's policies.

On other topics:

He said he will review a letter from Iran's leader but refrainedfrom directly responding to it. It's not something "that we shouldsimply do in a knee-jerk fashion," he said.

"We only have one president at a time," Obama said, addingthat he wants to be careful to send the signal to the world that"I'm not the president and I won't be until Jan. 20."