CHICAGO — President-elect Barack Obama called on Friday for the Bush administration and Congress to enact an economic-stimulus package, and he pledged to confront the country’s economic crisis “head on” the moment he is sworn in on Jan. 20.

“I do not underestimate the enormity of the task that lies ahead,” Mr. Obama said at his first news conference since his victory over Senator John McCain on Tuesday. He said he was certain that “some difficult choices” will have to be made.

“It’s not going to be quick, and it’s not going to be easy to dig ourselves out of the hole that we’re in,” Mr. Obama said, declaring that he wants to see “a rescue plan for the middle class” and a further extension of unemployment-insurance benefits.

The news conference here came immediately after Mr. Obama, Vice President-elect Joseph R. Biden Jr. and his newly named chief of staff, Representative Rahm Emanuel, met with the transition’s economic advisory board — and as a fresh wave of news from Wall Street and Washington deepened the gloom hanging over the country’s financial situation.

The government reported that the American economy lost another 240,000 jobs in October as consumers and businesses pulled back sharply, sending the unemployment rate to 6.5 percent from 6.1 percent, the highest level since 1994. And General Motors reported a larger-than-expected loss of $4.2 billion in the third quarter, a decline of 13 percent from the same period last year. The results came on the heels of similar dismal quarterly earnings from the Ford Motor Company.

The president-elect said he and his advisers would try to find ways to help the struggling automobile industry, and that he hoped to see enactment of an economic-stimulus package either before or soon after Inauguration Day.

“The auto industry is the backbone of American manufacturing and a critical part of our attempt to reduce our dependence on foreign oil,” he said. “I would like to see the Administration do everything they can to accelerate the retooling assistance that Congress has already enacted.”

Commenting on issues as varied as Iran and his family’s search for a suitable dog for the White House, Mr. Obama took care to thank President Bush for his warm remarks upon his election, and to pledge that he would do nothing between now and Jan. 20 to undercut the outgoing chief executive.

“We only have one president at a time,” he said.

Mr. Obama was cool and cautious when he was asked whether he had responded to a letter from President Mahmoud Ahmadinejad of Iran that marked the first time since the Iranian revolution that a leader in Tehran had congratulated an American election winner.

“I will be reviewing the letter,” he said, “and we will respond appropriately.”

Mr. Obama said he found Iran’s nuclear ambitions “unacceptable” and deserving of an international preventive effort. He said, too, that Iran’s support of terrorist organizations “is something that has to cease.”Projecting optimism despite the economic conditions, Mr. Obama said he was convinced that a new president can have “enormous impact.”

“That’s why I ran for president,” he said.

Near the end of the brief session, he alluded to a domestic choice facing his family: what kind of dog to bring to the White House. Perhaps, he said, the Obama family should visit a shelter and pick out “a mutt like me.”

Before the news conference, Mr. Obama received pledges of support from Republicans and Democrats alike.

“Republicans stand ready to work with President-elect Obama and our Democratic counterparts in Congress to enact an economic recovery bill that focuses on tax relief from working families and small businesses, rather than increased spending on government programs and higher taxes,” said Representative John A. Boehner of Ohio, the House Republican minority leader.

Harry Reid of Nevada, the Democratic majority leader in the Senate, offered similar sentiments. “This is a new chapter for our nation, and I am looking forward to working with my Democratic and Republican colleagues in Congress and President-elect Obama to return this nation to an era of increased prosperity for all Americans,” he said.

But the lawmakers’ remarks were hardly free of politics, as demonstrated by Mr. Boehner’s emphasis on tax relief, a common Republican theme, and Mr. Reid’s comment blaming President Bush’s “failed policies” for the economic crisis that Mr. Obama will inherit.

Mr. Obama has moved quickly on the transition, but his advisers put out the word on Friday that no cabinet-level appointments were imminent. The president-elect later said he planned to move with “deliberate haste,” and that “when we have an announcement about Cabinet appointments, we will make it.”

Mr. Obama announced his selection on Thursday of Mr. Emanuel as his White House chief of staff, a choice he said he made because Mr. Emanuel had “deep insights into the challenging economic issues that will be front and center for our administration.”

In a long list of forthcoming appointments, aides said, Mr. Obama is acting with the greatest urgency toward choosing a Treasury secretary and is said to be considering Lawrence H. Summers, who held the post during the Clinton administration, and Timothy F. Geithner, president of the New York Federal Reserve Bank.

No incoming president in modern times has been so pressured to begin governing, in effect, before he is sworn into office. With that in mind, Mr. Obama and Mr. Biden brought the group of high-profile financial and economic experts to confer.

Assembled to offer wide-ranging advice, the group of 17 included Mr. Summers and his predecessor as Treasury secretary, Robert E. Rubin; Paul A. Volcker, a former Federal Reserve chairman, and Eric E. Schmidt, the chief executive of Google. The billionaire investor Warren Buffett is to attend by speakerphone.

Other participants included Mayor Antonio R. Villaraigosa of Los Angeles; former Commerce Secretary William Daley; William Donaldson, former chairman of the Securities and Exchange Commission; Anne Mulcahy, chairman and chief executive of Xerox; Laura Tyson, former chairman of the President’s Council of Economic Advisors, and Gov. Jennifer M. Granholm of Michigan.

Ms. Granholm is a strong proponent of a stimulus package in the lame-duck Congressional session. Previewing her advice to Mr. Obama, she sent a letter to Congressional leaders on Thursday urging them to finance public infrastructure projects, extend unemployment and food stamp benefits and provide aid to states and the troubled auto industry.

Mr. Obama, who has declined to attend the president’s global economic summit meeting on Nov. 15, said he looked forward to meeting with Mr. Bush and the first lady, Laura Bush, at what might be the only get-together by the president and his successor before Inauguration Day.

“I thank him for reaching out in the spirit of bipartisanship that will be required to meet the many challenges we face as a nation,” Mr. Obama said.

On the economy, Mr. Obama is working with Democratic leaders in Congress on two stimulus packages. The first would be smaller, perhaps up to $100 billion, to be passed in a lame-duck session this month in hopes of getting Mr. Bush’s signature. The second would be larger, including tax cuts for low- and middle-income workers, to be ready as soon as late January.

Mr. Obama is coordinating with Congressional Democrats behind the scenes on the stimulus plans, which would include more jobless benefits, food stamps, aid to financially strapped states and cities, and spending for infrastructure projects that keep people at work. His chief liaison has been Mr. Emanuel.

Although the cooperation with the Democratic-controlled Congress is expected to go smoothly, the coordination with the Bush White House is a dicier matter. The Obama camp is feeling pressure from the administration, according to several people familiar with the situation, specifically from Treasury Secretary Henry M. Paulson Jr., to “co-own” the bailout program, which remains unpopular among voters despite a broad consensus that it was essential to avert wider economic collapse.

Mr. Paulson has sought Mr. Obama’s advice into the choice of a permanent director of the bailout program, and a commitment that Mr. Obama, once he is president, will keep the person on. But no decisions have been made about how Mr. Obama should proceed, advisers say.

Having promised change, Mr. Obama is not eager to join hands with Mr. Bush on the bailout.

But several Democrats said for Mr. Obama to stay aloof, as Franklin D. Roosevelt did before he succeeded Herbert Hoover amid the Depression, or to criticize the actions of the Bush administration could further destabilize financial markets as they seek clarity about the government’s policies. It would also mean that the Bush administration might take actions that would bind Mr. Obama’s hands as president.

A Treasury spokeswoman, Brookly McLaughlin, disputed the suggestions that Mr. Paulson was pressuring the Obama camp. Ms. McLaughlin in an interview cited a public statement from Mr. Paulson on Thursday in which he congratulated Mr. Obama and added, “A methodical and orderly transition is in the best interests of the financial markets, and Treasury is committed to making sure that the incoming team can hit the ground running in January.”