WASHINGTON (Reuters) - The White House said on Thursday it does not believe the Constitution gives the president an escape hatch to avoid a U.S. debt default if Congress fails to increase the borrowing limit before it is exhausted in about two weeks.

"This administration does not believe that the 14th Amendment gives the power to the president to ignore the debt ceiling," White House spokesman Jay Carney said at a briefing.

"Moreover, even if the president could ignore the debt ceiling, the fact that there is significant controversy around the president's authority to act unilaterally means that it would not be a credible alternative to Congress raising the debt ceiling," he added.

(Reporting By Mark Felsenthal; Editing by Sandra Maler)