President Trump said this in Turkey sitting next to the head of NATO.

Many "influencers" are pulling one sentence sound bites from this statement, that's wrong.  - Peggy Traeger Tierney

Here is basically what he said in full. 

You need to understand his entire statement in context to understand the meaning.
REPORTER: "Is the ceasefire with Iran over? Is the MoU dead?"

PRESIDENT TRUMP: “It's a very interesting question. To me, I think it's over. I don't want to deal with them. They're scum. They are led by sick people - sick, vicious, violent people. And if they had a nuclear weapon they would use it. As far as I'm concerned, it's over. I'll speak to our negotiators. They want to negotiate. They're good people - Steve Witkoff, Jared Kushner - but they have to come back to me. As far as I'm concerned, it's just a waste of time dealing with them. They're liars...