In a letter Wednesday to congressional leaders, Treasury Secretary Jack Lew established a hard deadline of Oct. 17 to raise the debt limit or risk default.
"Since August, we have received quarterly corporate and individual tax receipts and additional information regarding the activities of certain large trust funds, including military retirement trust funds. Treasury now estimates that extraordinary measures will be exhausted no later than October 17," he wrote.
"We estimate that, at that point, Treasury would have only approximately $30 billion to meet our country's commitments. This amount would be far short of net expenditures on certain days, which can be as high as $60 billion. If we have insufficient cash on hand, it would be impossible for the United States of America to meet all of its obligations for the first time in our history."
Lew called the House-passed GOP provision to prioritize payments to foreign creditors and Social Security recipients in the event that the limit is reached "ill-advised."
He reiterated that Congress must lift the ceiling and President Barack Obama will not negotiate over it.
Treasury Debt Limit Letter