Honestly what I really want to know is the mindset behind it.
I don't think I've ever seen anyone tell so many lies so frequently. Usually those lies are blatant falsehoods that are easily disproven by just about anyone. And they range anywhere from important and large issues to completely irrelevant ones nobody cares about such as crowd sizes. It's clearly pathological, don't think anyone could refute that.
It's one lie after another but during those moments, is it a conscious effort on his part? Is he thinking about his insecurities and narcissism and then proceeds to make a conscious decision to lie? Or is it more of an automatic impulse due to those factors with little or no thought behind it?
Furthermore, to what extent does he realize, if at all, that he is lying when and after he does it? Given the sheer frequency and absurdity of many of these lies I also think it's perhaps even more likely that the man is completely delusional and doesn't differentiate between actual reality and his version of reality. I would probably go with that option, which is the most worrying to me.
Either way, he is either detached from reality or he pretends to be.
Edit: Even if he did say "I would have a good relationship with Kim Jong Un", it's not exactly that much less delusional.