"I believe our prosperity has always come from an economy that's built on a strong and growing middle class," Obama said, noting that he has cut middle class taxes as president. "... So that's why I believe it's time to let the tax cuts for the wealthiest Americans, folks like myself, to expire."
Extend the tax cuts for the middle class now, and then let the result of the November election decide the debate on broader tax reform, including how much the wealthy should pay, the president said.
"He is 100% committed to it," Robert Gibbs said on CNN's "State of the Union."
The tax breaks are set to expire in what has become known as the "fiscal cliff," a package of spending cuts and the removal of tax breaks that will take place on January 1 if Congress fails to act. In total, they could add up to $7 trillion.
Tax breaks that would end include the Bush tax cuts, middle class protection from the Alternative Minimum Tax and more than 50 "temporary" tax breaks for individuals and businesses that have been on the books for years.
Obama also has backed the so-called Buffett Rule, named after billionaire investor Warren Buffett, which would impose a minimum 30% tax rate on those making more than $1 million. The measure was blocked by Senate Republicans in April.
Republicans say the solution to the country's deficit problems should focus on shrinking the size of government, rather than raising taxes on anyone.
"In the wake of another weak jobs report, the president is doubling down on his quixotic call for the same small businesses tax hikes that have been routinely rejected by the House and Senate," House Speaker John Boehner, R-Ohio, said in a statement Monday. "How will these small business tax hikes create jobs?"
House Majority Leader Eric Cantor, R-Virginia, said the chamber would vote later this month on a measure extending the Bush tax cuts for everyone for a year.
"Two years ago, President Obama said extending these same tax rates was 'the right thing to do' for the middle class, for jobs and for small businesses," Cantor noted, adding that "keeping taxes low is still 'the right thing to do' to get the economy growing again."
White House spokesman Jay Carney told reporters Monday that Obama would not sign the House measure if it reached his desk.