"We can't afford three, four, five, six more months where we're losing half a million jobs per month. And the estimates are that if we don't do anything, we could see 4 million jobs lost this year," Obama said during an appearance on ABC's This Week.
The president-elect is looking for Congress to pass what could wind up being a $1 trillion package of direct spending and tax cuts by the President's Day weekend. If it doesn't, he said, "Then Congress is going to hear from me."
Senate Democrats spent a rare Sunday afternoon meeting with Larry Summers, Obama's top economic adviser, to discuss the shape and details of the stimulus package, as well as how another $350 billion from the Troubled Assets Relief Program would be administered.
Lawmakers said they appreciated that the incoming administration was interested in their ideas and called the discussion "constructive" and "non-confrontational."
"It was a free exchange of ideas back and forth," said Sen. Ben Nelson, a Democrat from Nebraska.
Many senators have angrily complained that TARP - which is intended to strengthen the financial sector - lacked safeguards against mismanagement of funds. "This administration will have to deal with skepticism thanks to the failures of the last administration," said Sen. Kent Conrad, a Democrat from North Dakota.
A spokesman for the Obama transition team said they have no announcement about when a final package will be introduced on Capitol Hill.
During the Obama interview, which was taped Saturday, the president-elect acknowledged that he can't do everything he promised during the campaign, at least not right away, because of the economic quagmire.
"Our challenge is going to be identifying what works and putting more money into that, eliminating things that don't work, and making things that we have more efficient," he said.
"Not everything that we talked about during the campaign are we going to be able to do on the pace we had hoped."
In particular, he said, he was unlikely to close the Guantanamo Bay detention center in the first 100 days of his presidency.
"It is more difficult than I think a lot of people realize - and we are going to get it done - but part of the challenge ... is that you have a bunch of folks that have been detained, many of whom ... may be very dangerous, who have not been put on trial or have not gone through some adjudication," Obama said.
While some evidence against terrorism suspects may be tainted by the tactics used to obtain it, Obama said, that doesn't change the fact there are "people who are intent on blowing us up."
The president-elect described homeland security as his top priority, adding that terror attacks like the ones in Mumbai could happen here.
"We are going to have to stay vigilant, and that's something that doesn't change from administration to administration," he said.
"The dangers are always there. I think you have to anticipate, having seen the mayhem in Mumbai, there will be possible copycats."
On the economy, Obama said he's focused "on a pretty heavy lift" in getting Congress to pass his economic stimulus package, but he also plans to look at how the nation pays for government and how to make the system more efficient. That will include confronting a structural deficit in entitlement programs that eat up much of the federal budget.
Asked whether that would require sacrifice from everyone, Obama said: "Everybody's going to have to give. Everybody's going to have to have some skin in the game."
During the interview, Obama defended his nominee for attorney general, Eric H. Holder Jr., and predicted the Senate would confirm him despite questions about actions he took leading to President Bill Clinton's pardon of fugitive financier Marc Rich, among others.