WASHINGTON (AP) — Treasury Secretary Timothy Geithner is telling congressional leaders that the U.S. government will exhaust its borrowing limit as soon as mid-February, earlier than expected.

The government reached its $16.4 trillion borrowing limit on Dec. 31, but began using bookkeeping maneuvers to keep from surpassing it. In a letter to congressional leaders on Monday, Geithner says Treasury expects to exhaust those measures by mid-February to early March.

Geithner said he would provide a more precise estimate of when the government will reach that threshold once it moves closer to the deadline.