Sunday on ABC’s “This Week,” Senate Foreign Relations Committee chairman Bob Corker (R-TN) said President Donald Trump could not “charm” North Korea’s Kim Jong-un into giving up its nuclear weapons.

Partial transcript as follows:

GEORGE STEPHANOPOULOS: President Trump on that pending nuclear summit with North Korea. Want to talk about that more now with the chair of the Senate Foreign Relations Committee, Bob Corker of Tennessee. Senator Corker, thank you for joining us this morning. The president struck a more optimistic note in a tweet on Friday after that announcement from Kim Jong-un about freezing nuclear test spending then closing a major test site.

President saying this is very good news for North Korea and the world. Big progress. Look forward to our summit. You share that optimism?

SENATOR BOB CORKER: Look, I’m glad they’re meeting. I think all of us look at this with great caution and skepticism. This has been going on for 25 years and obviously Kim Jong-un has learned about public relations (ph) and is setting it up well for him. But I think everyone that’s been around this looks at this as just the beginning. It may lead to something, may not.

Let’s make sure the meeting and the context for it is all set up in the appropriate manner but we’ll have to see.

STEPHANOPOULOS: Let’s dig into what that — yes, let’s dig into what that means because a lot of people have pointed out that the concessions that Kim Jong-un has made are pretty easily reversible. He’s made them before.

CORKER: That’s right.

STEPHANOPOULOS: And then it’s going to set up the expectation for concessions from President Trump. So is this a — is this a — a danger? You know, some people talk about a freeze trap here, referring to that nuclear freeze that President Trump gives too much to get the meeting (ph).

CORKER: Yes, I think — I think people are well aware of exactly what you’re saying. I don’t see us giving any — giving up anything. I hope we will not — be put into (ph) policy right now is continue to put pressure on until something happens that’s productive. But this can be easily reversed. He obviously, as I mentioned, has learned a lot about public relations. But I think the president has people around him. You look at John Bolton, a great skeptic who will warn of any easing that might be considered.

STEPHANOPOULOS: Is it realistic to think that Kim Jong-un is actually going to give up his nuclear weapons?

CORKER: You know, George, you know this, he views having deliverable nuclear weapons as his ticket to dying as an old man in his bed. He saw what happened with Gaddafi.

Gaddafi’s a dead man now because he gave up his nuclear weapons. And so to think that somebody’s going to go in and charm him out of that is not realistic. Is there some progress that can be made? I hope so.

But, you know, it’s — that’s a big hurdle.

STEPHANOPOULOS: So — so leave that (inaudible) in there, what is the best case for one, the summit if it happens, and two, longer term negotiations with the north?

CORKER: Well, of course, best case is denuclearization, obviously. Is it realistic that he’s just willy-nilly going to do that? Absolutely not, but you know, progress can be made, freezing the program, who knows what he’s — what his ambitions are as it relates to South Korea.

But look, I think we go into this knowing we’ve got a huge problem, he’s gone way down the road with his nuclear activity, very close to having something that’s a danger to the United States, and I think beginning discussion we should hope for the biggest and just see where it goes.