WASHINGTON (CBS DC/AP) — The United States has hit its debt ceiling limit.

The Treasury Department will now be forced to resort to “extraordinary measures” to prevent a default on the nation’s debt after the U.S. reached its borrowing limit Friday.

Despite hitting the debt ceiling, Treasury Secretary Jack Lew stated in a letter to Congress last month that these “extraordinary measures” will only work until late February or early March to avoid default.

“The length of time that the extraordinary measures can extend the nation’s borrowing authority is significantly shorter than it was in 2011 and 2013. This is in large part because the government experiences large net cash outflows in the month of February, due to tax refunds,” Lew wrote in the letter, according to CBS News. “Moreover, this year the payment of tax refunds will be particularly concentrated in the weeks after February 7 due to the delayed start of the tax filing season, which was caused by the government shutdown.”

Before Congress left for the weekend, House Speaker John Boehner reassured Americans that the U.S. will not default on its debt.

“Look, we do not want to default on our debt, and we’re not going to default on our debt,” Boehner said.

Boehner added that “we’re still looking for the pieces to this puzzle” to get a deal done.

President Barack Obama has said he won’t permit Republicans to use the debt limit as a vehicle for GOP priorities. Two debt limit increases were enacted last year that included only modest add-ons, such as a provision forcing Senate Democrats to pass a budget.

“It’s the responsibility of Congress to ensure that bills that have already been incurred are paid in a timely fashion, so that the United States doesn’t default,” White House Press Secretary Jay Carney said on Thursday. “We are not going to pay ransom in return for Congress fulfilling this basic responsibility.”

Boehner is tempering expectations that the GOP might be able to extract much in exchange for an increase in the government’s borrowing cap – and he doesn’t sound optimistic he can accomplish it without help from Democrats.

“Mother Theresa is a saint now, but if the Congress wanted to make her a saint and attach that to the debt ceiling, we probably couldn’t get 218 Republican votes,” the speaker said.

Lifting the cap on the government’s more than $17 trillion debt is needed to permit the government to meet all of its obligations, including Social Security benefits, interest payments on U.S. treasuries, federal workers’ salaries and payments to federal contractors. Failing to do so would be unprecedented and, experts warn, could roil financial markets and the economy.

(TM and © Copyright 2014 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2014 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)