New Delhi: Over 40 per cent of the Russian forces on the Ukraine border are now in position for attack, and Moscow has started a campaign of destabilisation, a United States defense official said Friday, according to media reports. 


The official, who insisted anonymity, said that the United States, which estimates that Russia has placed more than 150,000 troops near Ukraine's borders, has observed significant movements since Wednesday, according to a report by news agency AFP.


Quoting the official, the AFP report said that forty to fifty per cent are in an attack position. “They have uncoiled in tactical assembly in the last 48 hours," the official further said.


Areas next to the border, where military units are set up in advance of an attack, are called tactical assembly points. 


According to the report, the official said that Moscow had massed 125 battalion tactical groups close to the Ukraine border, compared to 60 in normal times and up from 80 at the beginning of February. 


The official said that the increase in clashes between pro-Russian separatists and Ukraine government forces in the southeastern Donbas region of Ukraine, and inflammatory claims by officials in Russia and Donbas, show that the destabilisation campaign has begun. 


For weeks, Washington has warned that Russia could provoke or fabricate an incident in the area to serve as a pretext for invading Ukraine, the report said. 


According to the AFP report, US Secretary of Defense Lloyd Austin told ABC News' "This Week" that Russian President Vladimir Putin "has a number of options available to him and he could attack in short order."


"I don't believe it's a bluff," Austin said at ABC News' preeminent Sunday morning discussion program, according to the AFP report. "I think he's assembled... the kinds of things that you would need to conduct a successful invasion,” Austin added.


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Moscow denies the fact that it has plans to attack its western neighbour. However, Moscow is demanding a guarantee that Ukraine will never join the North Atlantic Treaty Organization (NATO), and that the Western alliance remove forces from Eastern Europe. The West has refused these demands, the AFP report said.


Russia invaded and occupied the Crimea region of Ukraine in 2014.


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