The U.S. Treasury is depleting its cash at an accelerating pace, drawing down its cash balance by $81.6 billion in the just the first four days of March, leaving the federal government with only $108.9 billion on hand, according to the Daily Treasury Statement released Monday afternoon.

A view of the U.S. Treasury Department in Washington
© AP File Photo/Evan VucciA view of the U.S. Treasury Department in Washington
At the beginning of February , the Treasury had $349.1 billion in cash on hand, but spent that down by $158.5 billion during the month, ending February with only $190.6 billion on hand.

Were the government to continue to draw down its cash balance at the $20.4 billion-per-day rate that prevailed in the first four days of March, it would spend its way through its final $108.9 billion in little more than five days.

Under current law, the U.S. Treasury may only run the national debt up to $14.294 trillion. At the end of February, according to the Treasury's Monthly Statement of the Public Debt , the total debt subject to this legal limit was $14.142331 trillion - just $151.669 billion short of the limit.

Had the Treasury not spent down the $81.6 billion in its cash balance in the first four days of this month and borrowed that money instead, it would have significantly reduced its remaining legal borrowing authority.

For the Treasury to borrow more than the current $14.294-trillion limit, Congress and President Barack Obama will need to enact new legislation authorizing the Treasury to increase the national debt up to whatever new limit they find agreeable.

The Treasury's largest single expenditure in the first four days of March, according to the Daily Treasury Statement, was paying off maturing debt. During those four days, Treasury paid $128.477 billion to redeem old bonds. At the same time, it borrowed $133.196 billion by selling new bonds.