Gov. Chris Christie is offering up support to New Jersey's Senate Republican candidate, Jeff Bell, but has been careful not to blast Bell's opponent, Sen. Cory Booker (D-NJ).

Governor Chris Christie and Mayor Cory Booker share a laugh at ribbon cutting of Teachers Village in Newark (Governor's Office/Tim Larsen)

Despite being on opposite sides of the aisle, Christie and Booker have had a notoriously amicable relationship.

In a statement through the Republican State Committee, Christie solicited donations for Bell's campaign.

"Recent polling continues to show that Jeff Bell is gaining momentum in this race - a poll released earlier this month showed Jeff to be within single digits in this race," Christie wrote.

Christie, though, tempered any criticisms of Booker in the mass email.

"But Jeff still faces an opponent who is well-known and well-funded by Washington special interests."

While Bell has closed the gap on Booker in the polls, he still faces an uphill climb to match the senator's war chest.

Christie has agreed to appear at two live events to raise money for Bell.