Going through the video to try to find the bit where the argument started. It's here. Nothing about Zelenskyy insisting on American boots on the ground.
Zelenskyy: The deal I signed with him, Macron and Merkel, and - was signed cease-fire, cease-fire. All of them told me that he will never go. We signed him with gas contract. Yes but after that, he broken the cease fire. He killed our people, and he didn't exchange prisoners. We signed the exchange of prisoners, but he didn't do it. What kind of diplomacy, JD, are you speaking about? What do you mean?
Vance: I'm talking about the kind of diplomacy that is going to end the destruction of your country.
Zelenskyy: Yeah but if -
Vance: Mr President, Mr President, with respect, I think it's disrespectful of you to come into the Oval Office trying to litigate this in front of the American media. Right now you guys are going around and forcing concripts to the front lines because you have manpower problems. You should be thanking the Presiden for trying to bring an end to this conflict -
Zelenskyy: You haven't been to Ukraine that you've seen what problems we have.
Vance: I have been to ... I've actually watched and seen the stories, and I know what happens is you bring people, you bring them on a propaganda tour Mr President. Do you disagree that you've had problems bringing people into your military? Do you think that it's respectful to come to the Oval Office of America
Zelenskyy: I will answer, I will answer -
Vance: ... and attack the administration that is trying to prevent the destruction of your country?
Zelenskyy: That's a lot of questions, let's start from the beginning.
Vance: Sure.
Zelenskyy: First of all, during the war, everyone has problems. Even you, but you have nice ocean. You won't feel now, but you will feel it in the future.
Trump: You don't know that, you don't know that.
Zelenskyy: God Bless, God Bless, God Bless you are not at war.
Trump: Don't tell us what we're gonna feel. We're trying to solve a problem. Don't tell us what we're gonna feel.
Zelenskyy: I'm not telling you -
Trump: Because you're in no position to dictate that. You are in no position to dictate what we're gonna feel.
Zelenskyy: I am -
Trump: We're gonna feel very good. We're gonna feel very good and very strong.
Zelenskyy: You will feel influence.
Trump: You're right now not in a very good position. You've allowed yourself to be in a very bad position.
<At this point Trump is repeating himself, talking over Zelenskyy, and it's hard to tell what Zelenskyy is trying to say.>