New Jersey Gov. Chris Christie and his wife, Mary Pat Christie, watch as President Trump signs a House resolution earlier this year. (Evan Vucci/AP)

New Jersey Gov. Chris Christie (R), a former chairman of Donald Trump’s transition team, said Monday that he repeatedly recommended that Trump not give a job to Lt. Gen. Michael Flynn, the former national security adviser now under investigation for potential collusion with Russia during the campaign.

“If I were president-elect of the United States, I wouldn’t let General Flynn in the White House, let alone give him a job,” Christie said during a wide-ranging news conference in Trenton, N.J.

Asked about Trump's recent characterization of fired FBI Director James B. Comey as a “nut job,” Christie said that was not his view.

“I would disagree with the characterization of Jim as a ‘nut job,’ ” said Christie, who as a former U.S. attorney interacted with Comey. “I’ve known Jim for a long time.”

Christie, who was relieved of his duties overseeing the transition shortly after the November election, declined to detail his concerns about Flynn.

“I’m not going to get into specifics,” Christie said. “Some of it involves classified information that I’m just not at liberty to discuss.”

Christie said that Flynn was “not my cup of tea” and that the two “didn’t see eye to eye.”

“I didn’t think that he was someone who would bring benefit to the president or to the administration,” Christie said. “And I made that very clear to candidate Trump, and I made it very clear to President-elect Trump. That was my opinion, my view.”

While he was running the transition, Christie said, “I was not informed in any way about him or anyone else being under investigation.”

If you're having trouble keeping track of former National Security Adviser Michael Flynn's ties to Russia and Turkey, here's what you need to know. (Gillian Brockell/The Washington Post)

Flynn's attorneys said in a letter Monday that Flynn will not comply with a Senate Intelligence Committee subpoena for documents related to its probe of alleged Russian meddling in the presidential election, invoking the Fifth Amendment right against self-incrimination.

Flynn was fired by Trump in February after it came to light that he had misled Vice President Pence and other administration officials about the nature of his contacts with the Russian ambassador.

Although Christie was kept out of the administration, he was recently named by Trump to lead a White House commission to combat drug addiction. Christie’s name has also been in the mix as a possible replacement to embattled White House staffers.

During the news conference, Christie offered some criticism of Trump's current staff.

“I think the president could be better served than he’s been served, and I think that leads to a lot of the confusion and a lot of the tumult,” Christie said.

He also repeated earlier criticism of how much time the president spends on Twitter.

“I think there’s also the president’s own approach on social media, etc., that tend to make it more difficult to have a coordinated approach to public communication,” Christie said.