Sunday on CBS’s “Face the Nation,” former Secretary of State John Kerry said President Donald Trump didn’t “know what he’s talking about.”

Partial transcript as follows:

BRENNAN: You tired to save this deal behind the scenes. That really angered President Trump. You were calling other foreign ministers —

KERRY: Well at that point in time the policy of the United States was still to support that agreement.

BRENNAN: But the president thought you were trying to undermine him.

KERRY: I was trying to have the policy of the United States of America, which is part of the agreement, to continue and common sense to continue. I didn’t negotiate. I spoke out. I will always exercise my right to speak out.

BRENNAN: President Trump would say he was elected on a platform of exiting this deal and he went out and attacked you personally because of the phone calls you were making.

KERRY: I don’t put any stock in that.

BRENNAN: He said ‘John Kerry never walked away from a table except to be in a bicycle race where he fell and broke his leg that’s it.’

KERRY: I did walk away. We almost walked away on two or three other occasions where we thought it was necessary. Really unfortunately, I say this sadly, you know, more often than not he really just doesn’t know what he’s talking about. He makes things up. And he’s making that up as he has other things.