It's in response to President Trump's plan to negotiate an end to the war directly with Russia.

News that Europe and Ukraine would be excluded from talks this week in Saudi Arabia has been met with anger and disbelief.

Joe Inwood reports.

The question is increasingly being asked.

If there is to be peace in Ukraine, what price must be paid?

The common position has always been this, as expressed by Oleksandr in Kyiv.

I would like us to get back all our territories, he says.

But is it possible?

I can't say at this stage.

I have faith and hope in it.

I think everyone wants this to happen.

The last few days at the Munich security conference have shattered that belief.

First, the new US defence secretary said Ukraine would have to give up territory and its ambitions to join NATO.

The reality of Ukraine membership in NATO as a part of a negotiated settlement is unlikely.

Then it was announced that President Trump had a 90-minute phone conversation with President Putin before speaking to his Ukrainian ally.

I had a good conversation with President Trump.

We had some phone calls and he had a phone call with Putin and he said to me, I think that Putin, that he wants to stop the war.

I said to him that he is a liar.

And then the news that talks would be held in Saudi Arabia to find a way to end the war.

This was the response of the US special envoy when asked if Europe, which has provided more support for Ukraine than the States, should be at the table.

Can you assure this audience that Ukrainians will be at the table and Europeans will be at the table?

The answer to that last question, just as you framed it, the answer is no.

The answer to the earlier part of that question is yes, of course the Ukrainians are going to be at the table.

It's put Europe in a difficult position, which risks it being excluded from the key decisions.

That will undoubtedly be under discussion at the emergency summit in Paris, convened by President Macron to work out a common position.

Now part of that, Sakhir Starmer writing in The Telegraph that the UK is ready and willing to contribute to security guarantees to Ukraine by putting our own troops on the ground if necessary.

I do not take that lightly, he says, but any role in helping to guarantee Ukraine's security is helping to guarantee the security of our continent and the security of this country.

President Zelensky has now arrived in the UAE, which has offered to eventually host peace talks.

The key question for the coming days, who should be at that table?

Jo Inwood, BBC News.

Our Europe editor Katja Adler is in Paris.

She told us more about what's at stake at the European leaders meeting.

Leaders coming here to Paris see it as a very small window of opportunity to send a clear message to Donald Trump that they are united and indispensable as a voice on Ukraine.

And they hope to do that by getting the ball rolling on two major issues demanded by Donald Trump.

Number one, that Europe spends more on its own defence.

And number two, that Europe sends troops to Ukraine in the case of an eventual ceasefire.

Of course, Sakhir Starmer isn't the only leader coming to Paris who has economic concerns at home.

But it's not about the fine print today.

It's not about the ifs and buts.

It's about getting that united front and a strong voice and message to Donald Trump to say, we've heard you.

We're taking action.

Now, sit us at that negotiating table to help decide Ukraine's future.

There's no knowing whether Washington will be listening, but the prime minister will hope to be that bridge between the US and Europe when he heads to Washington in a few days' time.

And Europe doesn't really have anything to lose, because if the US is eventually going to turn its back on Ukraine and on Europe in terms of security more broadly, then they're going to have to up their defence game in any case.

A very big focus at the meeting will be the idea of those troops in Ukraine.

It's a fraught question, because how many troops will Europe have to send?

The UK will be expected to send a big contingent.

For how long?

Under whose command will they be?

And what will be their mission statement?

For example, if Russia breaks the terms of a ceasefire agreement, would those troops be at war with Russia?

And where would the US be?

Would they have their backs?

So lots of questions.

And this meeting in Paris is just step one.

That was our Europe editor Katja Adler.

Meanwhile, Sweden's foreign minister says his country has not ruled out sending peacekeepers to Ukraine as part of a peace settlement.

His comments followed a similar statement from Sir Keir Starmer, who said he's ready and willing to put British troops on the ground in Ukraine if an agreement is reached.

Here's our political correspondent, Harry Farley.

It's a significant statement.

It's the first time the prime minister has expressed publicly a willingness to send British troops to Ukraine.

He says he writes in today's Daily Telegraph newspaper, with potentially putting British servicemen and women in harm's way.

But he argues that any role in helping to guarantee Ukraine's security is helping to guarantee the security of Europe and the security of this country, he writes.

There are questions for how this would work.

We heard from a former NATO secretary general at the end of last week saying that any force to guarantee a peace deal would need to be around 100,000.

And there's certainly no way that the UK military could maintain such a force in its current size.

So presumably, this would be with a coalition of other European countries.

All questions to be discussed and addressed by European leaders who are meeting today in Paris for an emergency summit.

And it comes after statements from the White House and U.S. officials over the last few days indicating that the U.S. focus is now not on European security and that Europeans, European countries must step up to guarantee their own security.

Our Paris correspondent Andrew Harding is following the European leaders' meeting.

So what do you know about what's on the agenda?

We don't.

The French are sort of playing things down at the moment.

They're saying this is not a formal summit.

It's an informal meeting of concerned European leaders from NATO, from the European Union and from France, Britain, Germany, Poland and other countries.

There is no formal agenda.

There will be no communique at the end.

But clearly, there is deep concern here, not just about long-term issues regarding increasing spending on defense budgets and also better integrating Europe's armaments industry, but focusing right now on what's going on between Washington and Moscow and making sure that Europe is at that table if peace negotiations, serious negotiations do go ahead, not just Europe, but Ukraine itself.

You heard there Harry talking about Sir Keir Starmer's potential commitment of troops to any future peacekeeping force.

Well, the French have already.

A year ago, Emmanuel Macron was talking about committing French troops.

That caused some consternation.

Other countries here, like Germany, are really far off that sort of commitment.

Poland may be more interested.

And I think Keir Starmer hoping to act as a sort of catalyst to nudge more European countries towards making that kind of commitment quickly, partly in order to remind Donald Trump that Europe is at the table.

It has a big stake.

It is the major contributor of arms and humanitarian support to Ukraine already.

And it cannot and should not be sidelined.

This is an informal gathering, Andrew, but do you get the sense that European countries have been caught off guard by the US's moves in recent days?

I think they've been caught off guard, shocked and angered by the speed and the ferocity of some of the American comments.

And they now need to sort of pick through the last week and work out what is rhetoric, what is comments designed for an American audience, and what was said more privately to European leaders that they can hopefully take more seriously.

And that, as they've sometimes put it, America is still talking, perhaps not to the US, behind the scenes about Europe being a serious ally, a serious partner, but clearly they've been rattled here by the vehemence of comments, particularly by the Vice President of the United States, who's really questioned European democracy and questioned the relationship, the whole nature of the future relationship between America and Europe.