Treasury Secretary Janet Yellen on Wednesday urged Congress to raise or suspend the U.S. debt limit, saying failure to do so would have "catastrophic" consequences for the U.S. economy. Speaking at a Senate hearing on the Treasury's budget, Yellen said she would plead with Congress to raise the limit "as soon as possible." A suspension of the debt limit expires after July 31. The Treasury would after that have to take so-called extraordinary measures to prevent the U.S. from defaulting, and Yellen told lawmakers that the point of default could come in August. Yellen earlier this year said her department was concerned that such measures would last a limited time.