Republican leaders in the House of Representatives notified members that a vote on raising the debt limit could come as early as Friday.
Treasury Secretary Jack Lew pleaded for quick action in the deeply divided Congress on raising the $16.7 trillion (£10.5 trillion) statutory limit on government borrowing, as he projected a 17 October date when borrowing capacity would be nearly exhausted and only $30bn would be left in his agency’s bank account.
The non-partisan Congressional Budget Office estimated that after 22 October Treasury might not be able to pay all its bills.
Amid the dire default warnings, politicians grappled with another potential crisis: federal agency shutdowns that could begin with the new fiscal year on 1 October unless Congress comes up with emergency funds.
The Democratic-led Senate voted unanimously to begin advancing legislation to avert government agency shutdowns.