Obama used Monday's Columbus Day holiday to visit a Washington charity, where he said that "if Republicans aren't willing to set aside some of their partisan concerns in order to do what's right for the country, we stand a good chance of defaulting".
The government went into partial shutdown at midnight Sep 30 after the Republican majority in the House of Representatives refused to pass a temporary funding measure - known as a continuing resolution - without a delay in the implementation of the Affordable Care Act, Obama's signature domestic initiative.
Even as the shutdown stalemate drags on, concern has shifted to the prospect of a US default if Congress fails to raise the debt ceiling by Oct 17.
House Republicans said last week that they were prepared to pass a temporary increase in the debt ceiling, but without ending the shutdown.
