"We know that we need insurance reform," Obama said.
"The health insurance companies are taking advantage of people. We know that we have to have some form of cost containment because if we don't, then our budgets are going to blow up."
Brown has promised to use his position as the 41st Republican vote to kill off the healthcare changes pushed forward by Obama, initial versions on which have been narrowly passed in votes in the senate and House of Representatives.
The different versions must now be reconcillied in vote in each of the chambers of congress before being signed off by Obama.
Brown told supporters during a victory speech on Tuesday in Boston: "Tonight, the independent voice of Massachusetts has spoken.
"People don't want this trillion-dollar healthcare plan that is being forced on the American people."
Brown replaces Edward Kennedy, the Democrat who held the Massachusetts seat for almost 47 years, died in August of brain cancer.
Paul Kirk, a Democrat, was appointed by the state's governor in September to occupy Kennedy's seat and will remain in the senate until Brown is sworn in.
Any delay in Brown taking up the post could give the Democrats time to push through the reforms, however, Obama has indicated that the Republican will be allowed to participate in any vote.
Obama said that it was time to come together around a bill that can draw Republican as well as Democrat support.
|Coakley's defeat raises the possibility of large Democratic losses in mid-term polls [Reuters]
Brown said that given the wide margin of his victory over Martha Coakley, the Democratic Party candidate, he should be allowed to take up the senate seat very quickly.
Obama acknowledged in the ABC interview that voter anger helped carry Brown to victory, but said: "People are angry, they are frustrated. Not just because of what's happened in the last year or two years, but what's happened over the last eight years."
Massachusetts last elected a Republican to the senate in 1972, but the weak economy and doubts about Obama's healthcare overhaul appeared to have moved some voters to abandon party loyalties.
More broadly, the election upset has raised the possibility of large losses for Democrats in mid-term congressional elections in November.
'Very real anger'
Al Jazeera's John Terrett, in Washington DC, said: "It's important to understand that Obama is seen differently here in the US compared to how he is seen overseas.
"There is a very clear message for the Democrats and that is that they have to wake up"
Toby Chaudhuri, Democrat strategist
"Looking in from overseas, he is erudite, articulate and professorial, a man concerned with many of the world's problems that perhaps the previous administration was not, and the world welcomes that," he said.
But in the US, Terrett said, there is "very real anger at the rising level of joblessness and the cost of the healthcare reform being pushed through the congress.
"Americans are also irritated with national security issues as embodied by the failed Christmas day airliner attack."
Terrett said Obama's "own base is angry about sending more troops to Afghanistan.
"Blacks, for example, are irritated that he doesn't take about race issues more, Latinos are concerned that there hasn't been the promised immigration reform and, of course, the Guantanamo Bay [prison] is still open.
"It's all this that Scott Brown tapped into while the Democratic Party candidate was aloof and distant."
Mitch McConnell, the senate Republican leader, said that Brown's victory was a clear sign that Americans had rejected Obama's healthcare proposals.
"They don't want this bill and want Washington to listen to them," he said.
|Massachusetts last elected a Republican to the senate way back in 1972 [GALLO/GETTY]
However, Harry Reid, the Democratic senate majority leader, said that politicians would continue to work towards healthcare reform.
"While Senator-elect Brown's victory changes the political math in the senate, we remain committed to strengthening our economy, creating good paying jobs and ensuring all Americans can access affordable health care," he said.
"We hope that Scott Brown will join us in these efforts."
Toby Chaudhuri, a Democrat strategist, told Al Jazeera: "Its a stunning victory and there is no question that Scott Brown fought a very clever campaign.
"There is a very clear message for the Democrats and that is that they have to wake up," he said.
"There will be a lot of debate here in Washington about what this means, not only for healthcare reform but also for Obama's administration."