WASHINGTON - President Barack Obama delivered a dire sales pitch for his massive economic stimulus package Monday night, facing millions of Americans for the first time since his inauguration to warn of a looming catastrophe if the bill doesn't swiftly become law.
  
"The plan is not perfect," a stern, forceful Obama said in the opening statement at his first prime-time, televised news conference, held in the stately East Room of the White House.

"No plan is. I can't tell you for sure that everything in this plan will work exactly as we hope, but I can tell you with complete confidence that a failure to act will only deepen this crisis as well as the pain felt by millions of Americans."

While his prepared remarks focused on the foundering economy, they were followed by questions from the White House press corps on a variety of issues, including Iran and bipartisanship.

Millions of Americans were expected to tune in, but Obama had a tough sell on his hands. Recent polls suggest half of Americans don't like the US$827 billion bill, believing it's too fat with unnecessary spending, even as Obama's personal approval ratings remain sky-high.

The president opted to hold his first formal White House news conference far earlier than many previous presidents. While John F. Kennedy held one just 10 days after his inauguration, most have waited months, including George W. Bush and Bill Clinton.

After weeks spent trying to reach out to Republicans to gain support for the bill -- including wining and dining them at White House soirees -- Obama criticized them Monday for suggesting the package is full of wasteful spending.

"When I hear that from folks who presided over a doubling of the national debt ... I want them not to engage in revisionist history. I inherited this."

A feisty Obama scoffed at the notion from Republicans that he was a big spender.

"I would love not to have to spend money right now ... that wasn't how I envisioned my presidency beginning."

Earlier Monday, Obama travelled beyond D.C.'s corridors of power to take his bleak sales pitch to the American people, visiting a heartland town decimated by the deepening recession to push for swift passage of the legislation.

Obama took a road trip to Indiana and spoke directly to America's economic casualties during a town-hall meeting in Elkhart, a city of just over 50,000 people where the jobless rate is twice the national average.

"We can't afford to wait," Obama said. "We can't wait to see and hope for the best. We can't posture and bicker and resort to the same failed ideas that got us in into this mess in the first place."

The Senate is expected to pass the bill on Tuesday after voting late Monday to end debate on the package.

But after its Senate passage, the stimulus package must be reconciled with the House's version of the bill -- meaning another few days of ferocious skirmishes between Democrats and Republicans.

Obama hopes to have the bill on his desk on Monday -- President's Day in the United States -- to sign into law. That means Congress will be working under a punishing deadline in the days to come.

Like he did in Elkhart hours earlier, the president warned again on Monday night that a failure to act quickly by Congress "could turn a crisis into a catastrophe."

The president is travelling to Fort Myers, Fla., on Tuesday, another region of the country hit hard by the recession, in Day 2 of his attempt to reach out to Americans and build public support for the bill.

In Fort Myers, dozens of people have set up camping chairs and blankets outside the city's convention centre to secure free tickets to the town hall event. Some 1,500 were given away.

"I get to see the president of the United States, in my town," Roy Hendrix, 51, a formerly homeless man, told the Miami Herald. "That's better than any rock concert or the World Series."

Like Elkhart, Fort Myers is located in a Republican-friendly region. The city's unemployment rate has climbed to 10 per cent from six per cent last year and its housing market is among the worst in the country.