U.S. President Barack Obama signs the economic stimulus bill during a ceremony Tuesday in the Denver Museum of Nature & Science. (David Zalubowski/Associated Press)

U.S. President Barack Obama on Tuesday signed into law a $787-billion US stimulus package his administration hopes will help lift the country's economy out of recession.

"I don't want to pretend that today marks the end of our economic troubles," Obama said before signing the legislation. "Nor does it constitute all of what we're going to have to do to turn our economy around. But today does mark the beginning of the end."

Obama signed the bill, which is the foundation of his administration's economic recovery plan, at the Denver Museum of Nature & Science to promote the stimulus package's push for "green" jobs in the energy field.

The package also includes funds for infrastructure and school investments, along with tax cuts.

"We have begun the essential work of keeping the American dream alive," Obama said.

The White House has established a website, www.recovery.gov, that will allow people to track where the money is being spent.

Battered by the subprime mortgage and credit crunch, the U.S. economy has been in recession since late 2007, shedding 3.6 million jobs in that time. In January alone, U.S. employers cut 598,000 positions — the biggest one-month drop since 1974.

"None of this will easy. The road to recovery will not be straight," he said, but adding he is confident that the struggling economy will be left behind.

Even as the first stimulus bill was being made law, the Obama administration said it has not ruled out a second boost for the economy. White House spokesman Robert Gibbs said the government would do what it takes to spur the economy, although he said there are no immediate plans for a second stimulus package.

Obama said the stimulus package won't constitute all of what will need to be done to turn the economy around. He is expected on Wednesday to unveil a $50-billion US plan to help homeowners stave off foreclosure.