WASHINGTON -- Treasury Secretary Timothy Geithner is giving Congress a little more breathing room to negotiate a deal that would raise the nation's borrowing limit.

In a new letter to congressional leaders, Geithner says he can delay an unprecedented default on the debt until Aug. 2, using a series of bookkeeping maneuvers to keep the government running.

That's a month longer than Geithner had previously said.

The U.S. government will hit its $14.3 trillion borrowing limit on May 16.

Republicans have said they will not vote to raise the debt limit without further spending cuts.