WASHINGTON (Reuters) - Russia lacks the munitions and troops to start a major offensive in Ukraine and would need to secure significant ammunition supplies from other countries beyond what it already has in order to do so, a senior NATO official said on Tuesday.
Briefing reporters ahead of the opening of NATO's annual summit, the official also said that recent arson attacks, assassination plots and sabotage in Europe are part of a covert campaign by Russian President Vladimir Putin to undermine public support for Ukraine.
On the battlefield, the official said Russia has been suffering "very high" losses as it struggles to exploit small territorial gains and lacks the troops and ammunition to mount a large-scale offensive.
"What they are having to do is order undermanned, inexperienced units to move into areas to achieve unrealistic objectives," said the official, who spoke on condition of anonymity.
"To sustain real offensive operations, we think that Russia would have to secure significant ammunition supplies from countries beyond what it is already getting from Iran and from North Korea," the official continued. "And Vladimir Putin would have to order a new large-scale mobilization."
Western and Ukrainian officials say Iran supplies suicide drones to Russia - a charge denied by Tehran - and North Korea has provided artillery shells and missiles to Moscow. Both deny that such transfers have taken place.
"We've seen Ukrainian defences improve significantly," the official said, adding that Kyiv also has sustained significant troop loses.
He estimated that Russia would be able to maintain its war economy for three to four more years.
Kyiv's forces have been on the back foot on the battlefield for months as Moscow's troops maintain heavy offensive pressure and advance slowly in the east of Ukraine.
NATO begins a three-day summit in Washington on Tuesday that Ukrainian President Volodymyr Zelenskiy is attending more than 28 months since Russia launched its full-scale invasion.
The official said "it will be some time" before Ukraine has amassed the munitions and personnel it needs to mount new large-scale offensive operations.
"We are seeing they're improving day by day," he added.
COVERT CAMPAIGN
NATO has responded to Russia's covert campaign to undermine European support for Ukraine by issuing two statements alerting Moscow that the alliance is aware of what it is doing, the official said.
It has also significantly increased intelligence sharing among alliance members so "we have a common picture of what's happening," the official said.
"The very first thing that you have to do when you're pushing back against something that Vladimir Putin believes is below the threshold... is to show him that we know what's happening," he said.
He also singled out what he said was China's continuing provision of "critical enabling pieces" for drones, missiles and the Russian defence industry.
The official said Putin "still thinks time is on his side" and is willing to endure "truly staggering numbers of military casualties."
Russia was recruiting about 30,000 troops per month, allowing it to sustain large battlefield losses, he said.
(Reporting by Jonathan Landay; writing by Tom Balmforth; Editing by Sharon Singleton, Angus MacSwan and Bill Berkrot)
By Jonathan Landay and Tom Balmforth
