"In the event that a debt limit impasse were to lead to a default, it could have a catastrophic effect on not just financial markets but also on job creation, consumer spending and economic growth," the report said.
"Credit markets could freeze, the value of the dollar could plummet, US interest rates could skyrocket, the negative spillovers could reverberate around the world, and there might be a financial crisis and recession that could echo the events of 2008 or worse."
International Monetary Fund chief Christine Lagarde said finding a way out of the debt limit dead end as soon uggs on clearance as possible was "mission critical."
The New York Times reported Thursday that Boehner had privately told House Republicans that he understood the dangers of a default and was ready to pass a debt limit increase with the help of minority Democrats if necessary.
Obama has refused to negotiate with Republicans over raising the debt ceiling, saying Congress is simply authorizing borrowing to pay bills it has already run up and that offering concessions would set a poor precedent for future presidents.