Former CIA director John Brennan denied Sunday he was the source of leaks about alleged contact between campaign associates of President Donald Trump and Russian spies.

In his first interview since leaving the job last month, Brennan told CBS News' "Face the Nation" that leaks of classified information are "appalling," but pushed back at GOP California Rep. Devin Nunes suggesting leaks were coming from Obama administration appointees "burrowed" inside the intelligence community.

"I certainly welcome that investigation to stop those leaks, because they … shouldn't be taking place and anybody who is responsible for that is dead wrong," he said.

"Anybody who thinks I am responsible it is dead wrong," he declared.

Brennan added it was "premature to be pointing fingers at anybody, whether in this administration or the previous administration" for being responsible for the leaks.

"As far as leaks of classified information are concerned, I agree that they are appalling and need to be investigated and need to stop, because the impact on our systems and our capabilities can be grave," he said.

Brennan also took aim at Trump's travel ban targeting seven Muslim-majority nations.

"Citizenship is not the indicator of terrorism," he said, adding: "The vetting process that needs to go on has to take into account multiple factors, not just countries of origin or where they might be departing from."

He said a travel ban won't help national security "in any significant way."

"It may sound good to have a ban against individuals coming from certain countries but you really need to take a look at what is truly going to mitigate the nature and the scope of the terrorist threat that we face," he said. "[The ban] sends a very bad message to individuals that are being singled out because of their nationality.

"It also gives a clear impression that there is an effort on the part of this administration to focus on Muslims themselves, so I think it is subject to various interpretations that do not help our national security."

Brennan also praised new national security adviser Lt. Gen. H.R. McMaster for rejecting use of the term "radical Islamic terrorism."

"He recognizes that these bumper sticker terms like radical Islam being responsible for terrorism does more harm than good," he said. "You need to be precise, and it is one of the things I think the president needs to realize is when he uses language it has resonance around the world…"

"Hopefully [he'll] be able to sway the thoughts and ideas and inclinations of some of the individuals who work with him at the White House complex."