Donald Trump is expected to support Ukraine for “as long as it takes to prevail” over Russia, the Defence Secretary has said.

John Healey said he believes the incoming administration will be “steadfast” in backing Kyiv, and downplayed concerns that the US will turn away from Nato under the president-elect.

But he cautioned that any potential peace talks were for Ukraine alone to call after a senior Trump adviser suggested Washington would be focused on resolving the conflict rather than helping the country regain territory.

It comes as Sir Keir Starmer meets French president Emmanuel Macron in Paris to discuss Ukraine on Armistice Day, amid ongoing uncertainty about the future of US backing for the country after Mr Trump’s election victory last week.

The Republican politician has insisted he would find a solution to end the war “within a day” without explaining how he would do so, which some have interpreted to mean a peace on terms favourable to Moscow.

Facing broadcasters on Monday morning, Mr Healey said he expected the new administration to continue backing Ukraine until it secures a victory over Russia.

“As far as President Trump goes, he recognises that countries get security through strength, just as alliances like Nato do, and I expect the US to remain alongside allies like the UK, standing with Ukraine for as long as it takes to prevail over Putin’s invasion,” he told Sky News.

He dismissed suggestions that a withdrawal of US commitments to Nato, which Mr Trump has previously alluded to, would leave the UK weakened.

“I don’t expect the US to turn away from Nato. They recognise the importance of the alliance. They recognise the importance of avoiding further conflict in Europe,” Mr Healey said.

Mr Trump has criticised Washington’s provision of tens of billions of dollars worth of aid to Ukraine since it was invaded by Russia, as well as expressing scepticism towards Nato and accusing European countries of free-riding on America.

On the weekend, Bryan Lanza, who worked on the Trump campaign, said the incoming administration would be focused on achieving peace rather than helping Ukraine gain back territory like Crimea, though a spokesperson for the president-elect later distanced him from the remarks.

This could be ended today if Putin withdrew following his illegal invasion … that’s the way this conflict could be ended, and the importance for us, for Europe and for the United States is that Putin in the long run does not prevail

Asked what the UK’s reaction would be to such a suggestion, Mr Healey told BBC Breakfast: “It’s Ukraine that gets to call when the talking starts. Our job is to support Ukraine, stand by them when they fight, stand by them if they decide to talk.

“This could be ended today if Putin withdrew following his illegal invasion… that’s the way this conflict could be ended, and the importance for us for Europe and for the United States is that Putin in the long run does not prevail, because if he does prevail, he will not stop at Ukraine, and the cost to us all will be much greater in the future.”

There have been suggestions that Sir Keir and Mr Macron could ask US President Joe Biden whether Ukraine can be given permission to fire long-range Storm Shadow missiles into Russia before he leaves the Oval Office.

Asked whether the two leaders were likely to talk about “anything that might happen before Donald Trump takes over”, Mr Healey said: “These are part of the discussions that have been going on for some time.”

It came as a row broke out over reports of a phone call between Mr Trump and Vladimir Putin in which the president-elect was said to have warned the Russian leader against escalation in the war.

Mr Healey had said on Monday morning that the UK welcomed the Republican politician’s intervention as “exactly right” when asked about the report in the Washington Post on Sunday.

However, moments later, the Kremlin denied that any call had taken place.

“This is completely untrue. This is pure fiction, it’s just false information,” Kremlin spokesman Dmitry Peskov told reporters in Moscow.

“There was no conversation.”

The spokesman reportedly attacked “the quality of the information that is published” even by “reputable” outlets.

Elsewhere, Mr Healey downplayed reports of a rift between the new Labour administration and Ukraine.

We’ve stepped up with more military support (for Ukraine). We’ve speeded up deliveries. We’re now spending more on military aid for Ukraine than ever before as a UK Government

He rejected suggestions that support had waned since Sir Keir took office after the Guardian reported officials in Kyiv had said relations had worsened and expressed frustration over Britain’s failure to provide additional long-range weapons.

Asked about the reported comments, Mr Healey said: “That is simply not correct.

“We’ve stepped up with more military support. We’ve speeded up deliveries. We’re now spending more on military aid for Ukraine than ever before as a UK Government, and I spoke at length to the defence minister in Ukraine yesterday.

“He certainly doesn’t see the UK support weakening, and he said the Ukrainians are confident in Britain’s continuing and steadfast support for their country.”