John Healey has declared his ambition to become the first Defence Secretary to deploy British soldiers to Ukraine.
With the fourth anniversary of Russia's invasion just days away, Mr Healey said: "I want to be the Defence Secretary who deploys British troops to Ukraine - because this will mean that this war is finally over."
He added: "It will mean we have negotiated peace in Ukraine. And a secure Europe needs a strong, sovereign Ukraine."
The Defence Secretary, writing in The Telegraph, insisted that 2026 must be the year the war finally ends.
There is "no heavier burden on any Defence Secretary or any Government than committing our Armed Forces on operations," he said.
Boris Johnson, meanwhile, has urged the UK and its allies to deploy non-combat troops to Ukraine at once.
The former PM told the BBC there was "no logical reason" why non-fighting forces should not be stationed in Ukraine.
"If we can have a plan for boots on the ground after the war, after Putin has condescended to have a ceasefire, then why not do it now?" he asked.
The Defence Secretary insisted that 2026 must be the year the war finally ends
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Mr Johnson also warned that Vladimir Putin would likely continue his aggression until the West demonstrated its commitment to Ukrainian independence.
He went on to describe the failure to act decisively after Russia annexed Crimea in 2014 as "tragic".
Britain and France have overseen months of talks with allies on forming a "coalition of the willing" to deploy peacekeeping forces once a deal ends the war.
Earlier in February, Mr Healey co-chaired meetings in Brussels with the 50-nation Ukraine Defence Contact Group and Nato defence ministers.
LATEST ON UKRAINE:
The MoD has put aside £200million to prepare British forces for a deployment on Russia's doorstep
|MINISTRY OF DEFENCE
Allies pledged approximately £25billion in military support for Ukraine during those discussions.
"We are stepping up military aid, and we will step up pressure on Putin further both through fresh sanctions and new action on the Russian shadow fleet," the Defence Secretary wrote.
"This war has shown us and Putin one important thing: never underestimate the will of the Ukrainian people," he added.
A Ministry of Defence spokesman said: "We are proud of UK leadership on Ukraine supporting the fight today and working to secure the peace tomorrow."
'This war has shown us and Putin one important thing: never underestimate the will of the Ukrainian people,' Mr Healey said
| GETTYHe said the Government had provided its "highest ever level of military assistance", including a half-billion-pound air defence package announced last week.
An additional £200million has been allocated to prepare British forces for potential deployment to Ukraine.
The UK is coordinating with more than 30 nations through the coalition of the willing initiative.
The spokesman confirmed that a multinational force under British leadership would secure long-term peace - and stressed the Prime Minister has made clear that British troops will only be deployed on the ground if and when the war stops.