"It is only government that can break the vicious cycle where lost jobs lead to people spending less money which leads to even more layoffs," he said.
Obama also said he was committed to maintaining a bipartisan approach to government despite failing to convince Republicans to agree to the bill quickly.
"Old habits are hard to break," he said of Republican opposition to the bill.
Republicans, and some moderate Democrats, have criticised the package, saying it contains too much unnecessary spending and too few tax cuts.
US senators voted 61-36 on Monday on a procedural motion to end their debate on the issue and hold a full vote on the package, after a week of wrangling between Democrats and Republicans over its details.
The same day Obama held a "town hall"-style meeting in Elkhart, Indiana, to push the case for the stimulus package to the US public.
He took a number of questions at the meeting, which was reminiscent of many held during his successful presidential election campaign last year.
The US House of Representatives has already passed one form of the stimulus bill, devoting more money to states, local governments and schools.
But the senate has its own version, which puts a greater emphasis on tax cuts in response to complaints from Republicans.
However, the two versions must be reconciled before both houses of congress can vote on - and approve - a final version.
Obama had last week imposed a deadline of February 16 to sign the bill into law. However, it is not clear if this deadline will be met.
The US economy is in recession after months of financial turmoil following the subprime mortgage crisis, tight credit conditions, rising unemployment and global financial upheaval.