Roughly 75% of Russian conventional forces deployed against Ukraine, US official says

Russian and Belarusian troops take part in joint military drills in the Brest, Belarus, on February 19. (Peter Kovalev/TASS/Getty Images)

According to the latest US intelligence assessment, Russia now has close to 75% of its conventional forces postured against Ukraine, a US official with direct knowledge of the intelligence told CNN.

The concentration of forces within striking distance of Ukraine is highly unusual and part of the reason the US believes Russia is ready to attack, the official said.

This includes some 120 of Russia's total estimated 160 Battalion Tactical Groups or BTGs which are positioned within 60km of Ukraine, according to the official. While that figure represents 75% of Russia’s principal combat units, it is less than half of the total troops in the Russian military.

US officials have reported that Russian troops combined with separatist forces could be as high as 190,000 deployed around Ukraine.

Some 35 of 50 known air defense battalions are deployed against Ukraine. In addition, the US estimates some 500 fighter and fighter-bomber aircraft are within range of Ukraine, as well as 50 medium to heavy bombers.

Together, the Russian forces now vastly outnumber Ukrainian military forces, according to the assessment.

To note: CNN cannot independently verify the intelligence.

On Thursday, the British Ministry of Defense tweeted an assessment that said, “Russia has over half of its ground combat power near the Ukrainian border.”