Janet Yellen, US treasury secretary, wrote in a letter to congressional leaders Friday that she was advising them “of the extraordinary measures that Treasury will begin using” to avoid breaching the debt limit.

Treasury Secretary Janet Yellen, in a letter on Friday to congressional leaders, said the Treasury would begin using extraordinary measures Jan. 21.

In one of her last acts as Treasury Secretary, Janet Yellen said her agency will start taking “extraordinary measures,” or special accounting maneuvers intended to prevent the nation from hitting the debt ceiling,