Republican debt-default deal crazy, says Obama
Mr Obama said he would "not negotiate on anything when it comes to the full faith and credit of the United States of America".
The President spoke out in a fiery speech at a community college just outside Washington, as Republican leaders in Congress said they would attempt to seek a one-year delay in the full implementation of the new national healthcare law known as "Obamacare" in return for raising the debt limit by enough to let Treasury borrow through the end of 2014.
A failure to raise the debt limit would mean that the US government could not borrow money from the markets to fund existing spending commitments. Such a move would trigger a US debt default, a potentially devastating outcome for a still fragile world economy.
"The Affordable Care Act is here to stay," Mr Obama said during a speech at Prince George's Community College in Maryland. "All this would be funny if it wasn't so crazy.
"The Tea Party Republicans have taken it to a whole new level because they're threatening to shut down the government or shut down the entire economy unless I agree to gut a law that will help millions of people.
He went on to chide the Republicans for some of the more hyperbolic attacks on his reforms to extend health insurance to millions of Americans currently without coverage.
He quoted the claim by a New Hampshire Republican state representative earlier in the summer that the health law was "a law as destructive to personal and individual liberty as the Fugitive Slave Act of 1850".
"Think about that," Mr Obama said. "Affordable Health Care is worse than a law that lets slave owners get their runaway slaves back."