Rival Democratic and Republican plans to raise the government's borrowing ability have thrust Congress into a standoff just one week away from a potentially devastating debt crisis.

The Senate on Friday firmly rejected a House Republican bill to slash spending and require a balanced-budget amendment, leaving unresolved with just days to go the urgent issue of increasing the nation's borrowing powers.

It's hard to know which is more surprising: a Democratic president pushing historic cuts in spending, including Social Security and Medicare. Or a Republican-controlled House refusing to accept the deal and declare a huge victory for long-sought GOP goals.

Negotiations to increase the nation's debt ceiling shifted to Congress where Republican and Democratic leaders were assessing the mood of their members even as an intricate but potentially face-saving deal to avoid an unprecedented government default was taking shape in the Senate.

Testy lawmakers and President Barack Obama headed back for a fifth day of debt-limit negotiations Thursday, pointing fingers at each other while trying to stave off a government financial default.

Testy lawmakers pointed fingers at one another and President Barack Obama on Thursday as negotiations over raising the national debt limit entered a perilous endgame. Wall Street eyed the standoff with growing anxiety, warning of catastrophe if the U.S. defaults on its obligations.

With compromise talks at a vituperative standstill, Senate Republicans unexpectedly offered Tuesday to hand President Barack Obama new powers to avert the first-ever government default threatened for Aug. 2.

Beset by a weak jobs report, President Barack Obama on Friday called for swift action by Congress to raise the nation's borrowing limit, saying the uncertainty over the debt ceiling has hindered hiring in the private sector.