Volodymyr Zelenskyy has suggested to Sky News that he might consent to Russia temporarily holding on to occupied Ukrainian territory as part of a ceasefire deal.
The Ukrainian president said such an arrangement could only be possible if land under his forces' control was taken "under the NATO umbrella" – allowing him to negotiate the return of the rest later "in a diplomatic way".
The comments, made during an interview with Sky News' chief correspondent Stuart Ramsay, have already caused a stir internationally. Here is what our correspondents made of it:
Zelenskyy appears to blink first – Putin will be pleased
By Ivor Bennett, Moscow correspondent
I think Vladimir Putin will be a happy man following this interview.
After being locked in a months-long stand-off over how the war ends, his opposite number appears to have blinked first, giving his clearest indication yet that Ukraine could be willing to cede territory (albeit not legally) in a peace deal.
As a man who doesn't like to back down, the Russian president will view this as a psychological victory.
The same goes for Zelenskyy's comments about being more afraid of losing people than land.
I expect Moscow will want to make the most of this.
It comes after a week of threats from the Kremlin in the wake of Ukraine firing Western weapons on Russian territory.
It's perfect material for the propaganda machine, which can spin it as a climb down by Kyiv in the face of Russian superiority.
That's likely to be the public response. In private, though, could Zelenskyy's apparent willingness to compromise promote similar movement here?
Ukraine war latest: Zelenskyy sets out conditions for potential ceasefire
Officially, Putin has two conditions for a ceasefire. The first is that Kyiv hands over, in their entirety, the four Ukrainian regions Russia has claimed and occupies the majority of. The second is for Ukraine to abandon its NATO ambitions.
The two are clearly incompatible in the scenario outlined by Zelenskyy – any ceding of territory is only if NATO membership is bestowed on the rest of the country.
But there are signs Putin is eyeing peace negotiations, after once again heaping praise on Donald Trump.
In comments he made on Thursday, the Kremlin leader described Trump as "intelligent" and "experienced", and said he believed the president-elect will "find the solution" to the war.
That doesn't sound like a man hell-bent on a military victory. Rather, someone who's trying to win the favour of the person who'll be chairing discussions.
Ukraine's leader is staking quite a bit on Trump
By Diana Magnay, international correspondent
Beyond ending the war within 24 hours, which is clearly unrealistic, Trump has been cagey on how exactly he'd manage it.
"Peace through strength" was what he declared he'd deliver as he nominated retired general Keith Kellogg to the post of special envoy for Ukraine and Russia on Wednesday.
Ukraine's leader is clearly staking quite a bit on Trump's presidency, hoping that if he shows a strong hand in supporting Ukraine, the rest of Europe will follow suit.
For Zelenskyy, NATO membership – and the solid security guarantee of Article 5, even if only an aspiration at this stage – is an inescapable part of how he sees his country's future.
From what we know of General Kellogg's proposals for peace, outlined in a policy paper back in April, NATO membership would be deferred indefinitely with Ukraine's security against further Russian aggression guaranteed instead by a strong bilateral security architecture.
So how much more cash and weaponry would Trump be willing to provide Ukraine to truly safeguard its security when the Republicans – and the US more broadly – want fewer foreign wars, not more?
For deterrence to work, Putin has to believe that when president-elect Trump says he'll act strong, he means it. And Ukraine has to hope that Trump doesn't tire of the process when he realises just how difficult it is.
Zelenskyy seems to be hinting at possibility of Russia talks
By Dominic Waghorn, international affairs editor
It's the language tone of President Zelenskyy in this interview that is intriguing. Does it represent a significant shift?
Eighteen months ago the Ukrainian leader told Sky's Kay Burley he had no interest in talking with Putin for peace talks.
Today he had this to say to Sky's Stuart Ramsay: "To talk just for talk, just for ambitions of Putin. Now, I think it's not smart. So we need to be in the position of strong position. And if we will be in a strong position, you will hear us."
President Zelenskyy can sometimes be cryptic. But he seems to be hinting at least at the possibility of talks with the Russians. As well he might.
Trump has made it abundantly clear he wants this war to end through negotiations.
To many, any deal that allows Russia to keep what it has taken by naked unprovoked force would be disastrous for the rules-based world order.
It has been compared to giving Adolf Hitler the Sudetenland in 1938 by Chamberlain et al at Munich. They hoped that would appease the German dictator, but it failed to deter him with devastating consequences for the whole world.
Ukrainians make that comparison often and ask what would stop the Russians from using any "peace agreement" to rearm and return stronger to take the rest of their country?
President Zelenskyy told Sky News he will need "guarantees that Putin will not come back".
Those guarantees will need to be cast iron this time, unlike promises made in the past to the Ukrainians by the West that ended in betrayal and emboldened Putin to launch his murderous invasion and war.
He knows NATO membership is not on the cards. Trump's team have made that very clear. But in this interview is he starting the bidding, starting high knowing he will have to settle for less?
The interview, between a wartime president in fatigues and Sky's war correspondent, is a fascinating exchange and will be pored over by policymakers in the Kremlin as well as the West as both sides prepare for what may be coming.
Concessions needed by both sides for this type of peace deal
By Deborah Haynes, security and defence editor
An invitation to join the NATO alliance requires all 32 member states to agree and cannot be extended to a country – like Ukraine – that is at war.
Should the fighting in Ukraine cease, though, there would still be huge resistance from some countries, Germany, Italy and Hungary just to name a few, about offering Kyiv membership to the club given the risk of the conflict with Russia reigniting – a move that would then draw the entire alliance into direct war with Moscow.
This anxiety is why it already took a lot of diplomatic pressure from some of Ukraine's strongest backers, including the UK, France, the Baltic states and Poland, to persuade all allies merely to sign up to a form of words stating that Ukraine is on an "irreversible path" to joining NATO.
However, experts have mused about a possible peace deal option that would see NATO offer membership to the government-controlled part of Ukraine, while Russia holds on to the land it's already seized but without any international legitimacy or recognition.
Such a move would involve concessions by both sides – with Kyiv forced to accept temporarily the loss of territory and Moscow failing to achieve a core war aim of preventing the majority of Ukraine from joining the Western alliance.
Even if Zelenskyy might be willing to countenance such an option, Putin would have to be forced to feel as though he has no greater chance of success through military force to do the same.
Just as important is what NATO allies think - and given the risk of war with Moscow it is highly unlikely that all member states would sign up to such a plan without significant pressure by whichever nations might be in favour.
If those nations do not include the United States then it is hard to imagine such a push having any chance of success.
(c) Sky News 2024: 'Vladimir Putin will be a happy man': Sky News' experts weigh in on exclusive Volodymy