New Jersey Gov. Chris Christie is not ruling out the possibility of being Mitt Romney's vice president.

During an appearance on the CNBC program Squawk Box, Christie said he would feel duty-bound to entertain a potential offer from the Republicans' apparent nominee. The hard-charging Christie is cited often as a possible running mate.

I love being governor of New Jersey, you can tell. But the fact is, if Governor Romney picks up the phone and calls, you have to answer the call and listen at least, Christie said.

Christie has established a reputation as an unapologetic conservative who debates opponents with gusto. He has led New Jersey down a cost-cutting path that's consistent with the Republican Party's emphasis on slashing deficits.