WASHINGTON (AP) — Treasury Secretary Janet Yellen told Congress Tuesday that she believed she would run out of maneuvering room to avoid the nation’s first-ever default soon after Dec. 15.

In a letter to congressional leaders, Yellen said that she believed Treasury could be left with insufficient resources to keep financing the government beyond Dec. 15.

Yellen’s new date is slightly later than the Dec. 3 date she provided to Congress in a letter to Congress on Oct. 18. That letter was based on the fact that Congress had just passed a $480 billion increase in the debt limit as a stop-gap measure.

As she has done in the past, Yellen urged Congress to deal with the debt limit quickly to remove the possibility of a potential default on the nation’s obligations.

“To ensure the full faith and credit of the United States, it is critical that Congress raise or suspend the debt limit as soon as possible,” Yellen wrote to congressional leaders.

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