US hits debt ceiling

There's more than just the fiscal cliff for lawmakers to worry about, the U.S. hit its debt limit on Monday.

The treasury department is already working to buy time through February to deal with the $16.4 trillion limit.

After that, the treasury will not be able to pay all of the country's bills in full and on time.

Congress must vote to raise the debt ceiling, creating yet another possible showdown on Capitol Hill.