President Volodymyr Zelensky has suggested that the parts of Ukraine under his control should be taken "under the Nato umbrella" to try and stop the "hot phase" of the war.

He was asked by Sky News whether he would accept Nato membership, but only on the territory that Kyiv currently holds.

Zelensky said he would, but only if Nato membership was offered to the whole of Ukraine, within its internationally recognised borders, first.

Ukraine could then attempt to negotiate the return of territory currently under Russian control "in a diplomatic way", he said in a wide-ranging interview.

But the suggestion is highly theoretical. Zelensky is not floating any new proposals - this was a television interview, not a diplomatic forum - but he is sending signals.

Whether Nato would ever consider such a move is highly doubtful.

“Ukraine has never considered such a proposal, because no-one has officially offered it to us,” Zelensky said.

Nato would need to offer membership to the whole country, including those parts currently under Russian control, he said.

"You can't give [an] invitation to just one part of a country," the president said, according to a translation provided by Sky News. "Why? Because thus, you would recognise that Ukraine is only that territory of Ukraine, and the other one is Russia."

Lots of people were proposing ceasefires, he said, but without a mechanism to prevent Russia from attacking again, ceasefires were simply too dangerous.

Only NATO membership, he said, could offer that kind of guarantee.

The Ukrainian president has already said that he thinks the war could end in the coming year if Ukraine’s allies show sufficient resolve.

Reports suggest that discussion of the so-called West German model - Nato membership offered to a divided country - has been going on in Western circles for more than a year.

But no formal proposals have yet been made.

Meanwhile, Zelensky has been keen to sound willing to engage with whatever proposals US President-elect Donald Trump might be considering.

“I want to share with him ideas, and I want to hear from him, his ideas,” Zelensky said.

The Ukrainian leader said he would be sending a team in the coming days to meet Trump officials, including the president-elect’s recently appointed special envoy for Ukraine, retired general Keith Kellogg.

In April, Gen Kellogg co-authored a plan, called America First: Russia & Ukraine, which would freeze the front lines in Ukraine and pressure both Kyiv and Moscow to come to the negotiating table.

Future US military assistance to Ukraine would be conditioned on Kyiv’s willingness to enter peace talks, so goes the plan.

But in the event of a ceasefire, Washington would continue to provide military assistance and “strengthen [Ukraine’s] defences to ensure Russia will make no further advances and will not attack again after a ceasefire or peace agreement.”

Under the proposals, NATO membership for Ukraine would be put off for an extended period.

For Zelensky, this begs a crucial question: what guarantees of security would the Trump administration be willing to offer?

“Without NATO, it’s not real independence for Ukraine because he [Russian President Vladimir Putin] will come back,” Zelensky insisted.

The differences between Zelensky’s peace plan and the nascent Trump policy are still substantial.

But by engaging with the idea of a ceasefire and painful territorial sacrifices (in the short term at least), the Ukrainian leader is doing his utmost to sound constructive, conscious that there are so far no equivalent signs coming from Washington.

Russia annexed the Crimean peninsula in 2014. Eight years later, it launched a full-scale invasion of Ukraine and has occupied territory in the country's east.

But It is also worth noting that so far Putin has given absolutely no indication that he’s abandoned his desire to subjugate Ukraine entirely.

The idea that he would be willing to allow any part of Ukraine to join Nato is, for now, unthinkable.

All the indications so far suggest that any involvement of Nato is a complete non-starter.

On Thursday, Moscow mounted its second mass attack on Ukraine’s energy infrastructure in less than two weeks.

Putin called it a response to "continued attacks" using US-supplied Atacms missiles on Russian soil.

Having already endured two-and-a-half bitter winters since Russia’s full-scale invasion in February 2022, Ukrainians are bracing themselves for another.