New Jersey Gov. Chris Christie on Sunday contradicted some Republicans calling for Robert Mueller's resignation from the Russia probe because he has not seen any evidence of "an absolutely indisputable conflict" with the special counsel's investigation into possible links between the Kremlin and President Trump's campaign.

"I have not yet seen anything that makes me think he must step down, that there's absolutely indisputable conflict," Christie told CNN. "But I think he's got to be careful and be watching this all the time."

Christie said his warning was based on the importance of public perception surrounding the probe, which is also looking into the extent of Moscow-directed meddling in the elections that took place in 2016.

"Listen, I think that he has to be very, very careful about making sure that the public believes that he has no conflicts and that his integrity is unquestioned," Christie said. "And I think that, you know, Director Mueller has to continue to review that with his own legal staff.

Christie also repeated claims Trump is not the subject of Mueller's investigation, despite earlier slamming grand jury leaks as criminal violations of the process' secrecy and confidentiality measures.

"The last news that we've received, Jake, publicly is that the president was told he's not under investigation," Christie told CNN's Jake Tapper. "We've heard nothing to the contrary, so I'm making that statement off of the public information that we've already been given."

The first charges under Mueller's probe are expected to be laid as early as Oct. 30.