US Now Faces Even 'Tougher' Debt Crisis: Sen. Shelby

Sen. Richard Shelby told CNBC on Thursday that he voted against the "fiscal cliff" deal because it didn't solve anything but move us from one crisis to another in "less than" eight weeks.

Shelby was referring to the fact that the bill now signed into law only delayed the automatic spending cuts known as the "sequester" for two months.

This sets the stage for a new round of negotiations between President Barack Obama and Republicans over how to reduce government spending and shrink the deficit.

(Read More: Obama Now Has Less Leverage: Former OMB Director )

"I believe it's going to be tougher [this time]," Shelby said in a "Squawk Box" interview. "I hope the president will get involved."

The Alabama Republican said he'd like to see an effort made to reform entitlements, including increasing the retirement age over time to 70 years old and changing the way benefit increases are calculated using the Chained Consumer Price Index.

The president has said that any new negotiations won't include the debt limit.

"I've heard that before," Shelby said. "[Obama] drew the line in the sand. That's not concrete." A decision on whether to raise the nation's $16.4 trillion borrowing limit will need to be made soon.

The last debt-limit fight between the president and Republicans in 2011 resulted in a Standard and Poor's downgrade of the sterling credit rating of the U.S. S&P said the recent cliff deal won't change its outlook. Rival credit agency Moody's also warned that the U.S. must do more to reduce the deficit.

As if all this wasn't enough, the government faces a shutdown at the end of March if Congress doesn't approve new funding for federal agencies.

(Read More: Republicans Start New Congress Bruised and Divided )

Shelby said he's assuming the post of ranking member on the Senate Appropriations Committee and he wants spending bills to be brought to the floor in a more transparent way.

—By CNBC's Matthew J. Belvedere; Follow him on Twitter @Matt_SquawkCNBC