WASHINGTON — The federal government will not run short of money to pay its bills on May 16, when the federal debt reaches the legal maximum of $14.3 trillion.

Even after Aug. 2, the deadline the Treasury Department set this week for Congress to lift the borrowing limit, the government might be able to delay a crisis, perhaps even for a few months, through extraordinary measures such as asset sales.

But with every passing week of stalemate over the debt ceiling, the risk increases that investors will start to fret that the United States will not pay its debts, and demand higher interest rates for loans to the federal government.

Should that happen, the cost could be vast and the damage difficult to reverse.

Debates over the debt ceiling are a regular feature of political life in Washington. Congress has lifted the ceiling more than once a year, on average, over the last half-century — often right before the deadline. But the debt has never been so large, and the political climate has rarely been as contentious.