Defence Secretary Ben Wallace has said he will “believe it when we see it”, when asked about Russia withdrawing from the Ukrainian city of Kherson.
It would be a “significant psychological blow” for Russian troops if they left the southern city, he said.
He was speaking at a meeting of ministers from the Joint Expeditionary Force nations in Edinburgh.
The defence alliance of 10 European countries recommitted its support for the “sovereignty and territorial integrity” of Ukraine, with the Netherlands contributing an extra 100 million euro (£87 million) to finance military material.
Along with other ministers, Mr Wallace stressed it is Ukraine’s choice whether they enter peace talks with Russia.
He said: “What we’ve all been helping Ukraine fight for is the right to choose.
“It’s not for me to tell Ukraine what it shouldn’t negotiate on.
“More important than what they do with their choice is that they have the right to choose as a free sovereign state without pressure, without a gun to its head from the Kremlin.”
Discussing Kherson, he said the city is the only major objective Russia had managed to take and hold during the war.
Russian military leaders have said they will withdraw from the city and form a new defensive line on the east bank of the Dnieper river, but Ukrainian leaders have been cautious as to whether this has actually taken place yet.
Mr Wallace said: “It must be quite a significant psychological blow that the one objective they did manage to capture, they have announced their intention to leave.
“Of course this is Russia, so we haven’t yet seen them leave en masse.
“We will believe it when we see it and I think we should all be cautious, as (Ukrainian) President (Volodymyr) Zelensky was, that there is still Russian tricks and all sorts of things.
“But if they do pull out of Kherson it does beg that broader question of what was it all for?
“What was all the tens of thousands of deaths for when every one of their major objectives they have failed to hold or capture since February.”
The world should not be grateful if Russia hands back “stolen property”, he added.
Mr Wallace was also asked about reports that a British national has been killed fighting in Ukraine.
He said he regrets the loss of any life and the person in question was fighting with Ukrainian forces.
He said: “We made our position clear early on that if you want to help contribute as a British citizen, there’s the armed forces that you can contribute to in the UK.”
The minister said he understands the “strength of feeling” around the war, saying it is important to remember tens of thousands of Ukrainians have died defending their country.
Following the meeting, Netherlands defence minister Kajsa Ollongren said the new funding would allow Ukraine to procure military aid directly from industry.
Speaking to the PA news agency, she said it was important to “wait and see” what happened around Kherson.
She said: “Russians were under a lot of pressure on that front.
“So it seems quite logical for them to retreat from Kherson but it’s also a big defeat from their perspective.
“If they actually do retreat that means that the winter period might be sort of a stalemate.
“But from the Ukrainian perspective, (they are) in a much better shape than the Russian armed forces are right now.”