Russia has "strategically lost" the war in Ukraine and is a "more diminished power", the head of the UK's armed forces has said.
Admiral Sir Tony Radakin said Vladimir Putin had used 25% of Russia's army for only "tiny" gains.
And although Russia may achieve "tactical successes" in the coming weeks, he said any notion the war had been a success was "nonsense".
War at 'pivotal moment' in Donbas - Ukraine latest updates
Sir Tony, who is the UK's chief of defence staff, said Russia was running out of troops and advanced missiles and would never be able to take over all of Ukraine.
His comments come as Ben Wallace, the defence secretary, told Sky News it is "highly likely" that the UK will add many hundreds more troops to a NATO force in Estonia tasked with further deterring Russia.
Sir Tony said: "This is a dreadful mistake by Russia. Russia will never take control of Ukraine.
"Russia has strategically lost already. NATO is stronger, Finland and Sweden are looking to join."
He said Moscow had been forced to give up its objectives of taking over most Ukrainian cities and was now engaged in a tactical battle in which fighting is "tough".
Read more:
Ben Wallace talks to Sky's Deborah Haynes
Ambulances 'covered in blood' and 'nothing is safe' in Donbas
Is Putin really ill? Why are there rumours about his health?
Sir Tony said: "The Russian machine is grinding away, and it's gaining a couple of - two, three, five - kilometres every day.
"And that's tough for Ukraine, but this is going to be a long fight. And we're supporting Ukraine, Ukraine has shown how courageous it really is.
"And Russia has vulnerabilities because it's running out of people, it's running out of hi-tech missiles."
He continued: "President Putin has used about 25% of his army's power to gain a tiny amount of territory and 50,000 people either dead or injured."
Russia is now a "more diminished power" diplomatically and economically than several months ago, he said.
"Any notion that this is a success for Russia is nonsense. Russia is failing.
"It might be getting some tactical successes over the last few weeks. And those might continue for the next few weeks.
"But Russia is losing strategically."
Key developments in Ukraine:
• EU leaders support Ukraine's bid to join the bloc
• UN says deaths resulting from the battle for the key port city of Mariupol are likely to be "in the thousands" and "gross violations" of international human rights law occurred
• At least four people were killed and seven wounded after an airstrike hit the eastern city of Lysychansk
• A total of 660 Ukrainian families in England are either homeless or at risk of homelessness after their accommodation was unavailable, it has been revealed
Sir Tony said he was in touch with his Ukrainian counterpart, General Valerii Zaluzhnyi, who recognised they were in a "tough battle" in the east.
The defence secretary admitted on Thursday that Russia outnumbered Ukraine in artillery fire by 20 to one in some areas.
But Mr Wallace told Sky's defence and security correspondent Deborah Haynes that, because allies were starting to give Ukraine long-range artillery and rocket systems, they would soon be able to make "significant progress in the east of the country".
Sir Tony paid tribute to Ukrainians. "They're courageous people," he said. "They're ingenious people in terms of how they're taking the fight to the Russians.
"But they're also honest people, with saying actually they need some help."
He said the UK would continue its support for Ukraine and "we're in this for the long haul".
Earlier this week Mykhailo Podolyak, Ukrainian presidential adviser, urged the West to help his country achieve "heavy weapons parity" with Russia in the war, calling for more heavy artillery, rocket systems and vehicles.
Sir Tony said he was "wary" of phrases such as parity as no single capability would determine the outcome of the war.
The UK is providing MLRS rocket systems and has recently delivered 120 armoured fighting vehicles, he said.
"We've been providing anti-tank weapons, there are other elements that we're providing and that will continue," he said.
"But it's the mass that's provided by the whole of the international community - and it's putting that alongside the courage and the resolve of the Ukrainian armed forces to fight for their territory.
"That is where the real parity lies, and where the real strength of Ukraine lies."
https://news.google.com/__i/rss/rd/articles/CBMimgFodHRwczovL25ld3Muc2t5LmNvbS9zdG9yeS91a3JhaW5lLXdhci1ydXNzaWEtaGFzLXN0cmF0ZWdpY2FsbHktbG9zdC1hbmQtYW55LW5vdGlvbi10aGV5LWhhdmUtYmVlbi1zdWNjZXNzZnVsLWlzLW5vbnNlbnNlLXRvcC1taWxpdGFyeS1jaGllZi1zYXlzLTEyNjM1MzEy0gGeAWh0dHBzOi8vbmV3cy5za3kuY29tL3N0b3J5L2FtcC91a3JhaW5lLXdhci1ydXNzaWEtaGFzLXN0cmF0ZWdpY2FsbHktbG9zdC1hbmQtYW55LW5vdGlvbi10aGV5LWhhdmUtYmVlbi1zdWNjZXNzZnVsLWlzLW5vbnNlbnNlLXRvcC1taWxpdGFyeS1jaGllZi1zYXlzLTEyNjM1MzEy?oc=5
2022-06-17 05:28:10Z
1467850194