JOHN YANG: Good evening.

I'm John Yang.

Tonight, Washington and European capitals are still feeling the reverberations of yesterday's heated Oval Office exchange between President Trump and Ukrainian President Volodymyr Zelenskyy.

Hours after Mr. Trump scolded Zelenskyy for not showing enough appreciation for U.S. support, the Ukrainian leader posted on X.

We are very grateful to the United States for all the support.

I'm thankful to President Trump, Congress for their bipartisan support and the American people.

He also reiterated his opposition to a quick ceasefire that President Trump wants, saying Russian leader Vladimir Putin can't be trusted.

Now Zelenskyy is in London to rally the support of European leaders.

Today he met with U.K. Prime Minister Keir Starmer, and tomorrow he'll attend a European summit in London to discuss the way forward.

Kurt Volker is a former U.S. Special envoy to Ukraine and a former U.S.

Ambassador to NATO.

Mr. Volker, what do you expect to come out of this European summit tomorrow that Zelinsky is attending?

KURT VOLKER, Former Special Envoy to Ukraine: Well, I think there are some good things that we've seen already, these expressions of European support and solidarity for Ukraine.

I think it's important for Zelenskyy psychologically.

I think it's also important for the Ukrainian people.

But I hope that behind closed doors they're actually talking about what kind of things need to be done to get Ukraine and the United States and Europe all on the same page again.

We can't be creating a dynamic of Europe and Ukraine against the United States.

We all have to pull together.

And there I think it's going to be a matter of Europe being willing to put on the table forces for security assurances for Ukraine.

And I think it's got to be President Zelenskyy saying that he wants peace.

He wants to have a ceasefire.

He will agree to one as soon as Putin to get things back on track with the U.S. as well.

JOHN YANG: If U.S. aid were to be cut or even go away, could Zelenskyy, could Ukraine go on with just European support?

Are there enough forces and hardware to keep them going?

KURT VOLKER: It's not enough.

It's good.

It is supportive.

It'll buy Ukraine time.

But the U.S. provides many unique capabilities, including intelligence, satellites, training, equipping, logistics.

There is so much that the U.S. is doing here that is vital to.

This is not enough Europe on its own, although it is very important that Europe play a major role.

JOHN YANG: You say it's important to get all three sides, Ukraine, United States and Europe on the same side, but in European capitals, aren't they seeing what happened yesterday and him, the way he talked and the way he talked about the war in Ukraine.

A message to Europe that you're on your own.

I mean, war in Ukraine, obviously, is about European security to the European leaders.

KURT VOLKER: No, I don't think that was the message.

I think the message was that we got to get Putin to the negotiating table.

You don't want to bash Putin, criticize him personally, and then never get an end to the war.

If you want to end the war, you got to get Putin to the negotiating table.

Basically taking a position that is firmly fighting against Putin.

Trump is not going to do that he wants to actually end the war right now.

And so he's being careful not to position himself that way.

Unfortunately, what happened in that meeting, Zelenskyy, I think, missed a real opportunity to get the U.S. and Ukraine in alignment.

Trump has been putting together this concept, if you will, of ceasefire reciprocity with Ukraine, where we get paid back for military assistance.

So it's a fair deal for the American people.

Deterrence in terms of security assurances and European presence so Putin doesn't attack again, and improving the burden sharing ratio so that Europe does more, the US does relatively less.

JOHN YANG: But since this meeting, he's also said that he doesn't want a quick ceasefire because he doesn't think Putin will keep his commitments.

Clearly, that's what President Trump wants.

How do you bridge that gap and save this relationship?

KURT VOLKER: Yeah, exactly.

And Zelenskyy needs to reframe the way he's talking about this.

Saying he doesn't want a ceasefire because he doesn't trust Putin is the wrong way to say it.

The way to say it is he wants a ceasefire as soon as Putin agrees to do that as well.

And it will never be Ukraine that is the first to break.

But if Putin breaks a ceasefire, Ukraine will defend itself.

He needs to flip it back onto Putin and say that Ukraine is willing and ready for peace.

It's Putin.

That's not.

JOHN YANG: Yesterday in the Oval Office meeting, we saw a continuation of a pattern of President Trump not criticizing Putin, as a matter of fact, expressing sympathy with Putin while excoriating the leader of the country that Putin invaded.

Why is that?

KURT VOLKER: Well, I think you have to go back to earlier in the meeting.

Trump was very positive towards Zelenskyy toward Ukraine praising Ukrainian soldiers.

He was setting this up to be very positive for Zelenskyy.

And it was only after Zelenskyy then responded to J.D.

Vance talking about diplomacy that it became a bit of a back and forth in an argument.

And then you saw Trump lash out and criticize President Zelenskyy.

As far as Putin goes, Trump is trying to avoid personalizing and demonizing Putin because he needs to get Putin to the table.

And I think President Trump thought he was getting this all together.

He was moving Putin that way.

He was working with President Zelenskyy.

He was shaping a deal that would put the U.S. And Ukraine in alignment.

And then that discussion, the Oval Office just got out of hand and blew everything up.

JOHN YANG: Former Ambassador Kurt Volker, thank you very much.

KURT VOLKER: Thank you.