Lew informed Congress in a letter the Treasury Department can, as it has done before, use extraordinary measures to keep paying obligations after Feb. 7. However, he said he can see no "reasonable scenario" under which the department can sustain that for more than a few weeks, the Hill reported.
The debt limit was suspended this fall as part of an agreement in Congress to reopen the federal government following a shutdown.
Lew urged Congress to raise the debt limit "at the earliest possible moment" to alleviate the threat the federal government might default on its obligations. He noted Congress just passed a bipartisan two-year budget deal and said raising the debt ceiling will "protect the full faith and credit of the United States."
Rep. Paul Ryan, R-Wis., who as chairman of the House Budget Committee negotiated the bipartisan budget deal, said this week congressional Republicans will pressure Democrats to cut spending further as a condition for raising the limit. Senate Minority Leader Mitch McConnell, R-Ky., said this week he doesn't think Congress will pass a so-called clean debt limit increase.
Lew said in the letter Thursday the nation's creditworthiness "is not a bargaining chip to be used for partisan political ends."
The White House has maintained raising the borrowing limit is not debatable.
Notable deaths of 2014 [PHOTOS]