New Delhi, Mar 2 (IANS): Russia has lost roughly 3 to 5 per cent of its tanks, aircraft, artillery and other military assets inside Ukraine, compared to Ukrainian losses of roughly 10 per cent of its capabilities, according to two US officials familiar with the latest intelligence reports, CNN reported.

But the stark imbalance underscores grim assessments from the US and western officials that despite a stiffer-than-expected resistance by Ukraine that has kept major cities out of Russian hands, it is still likely to be overwhelmed as Russia launches an intensified and less discriminate phase of its assault, CNN reported.

And even despite western assistance, US officials say Ukraine is still vastly outgunned by Russia. Moscow has initially leaned heavily on its more modern precision cruise missiles, according to a source familiar with the intelligence, heavily degrading Ukraine's military infrastructure. Meanwhile, Ukraine has continued to burn through its supply of shoulder-fired Javelin missiles, the report said.

US officials believe that Russia is now changing tactics, an American official said.

While Moscow started off with a more modern combined arms approach - one that also appeared to eschew targeting civilian infrastructure - it has now shifted to what this official called a strategy of "slow annihilation".

Officials anticipate continued heavy weapons bombardment and the possibility that "tens of thousands" of troops will march on major Ukrainian cities, the US official said.

Another western official said that there is a sense that the conflict may be shifting to a grinding war of attrition - not the flash campaign that both Russian President Vladimir Putin and US intelligence had suspected would cause the fall of Kiev in a matter of days, CNN reported.