Russian forces are on the offensive on the border with Ukraine

More than 40% of Russian troops on the border with Ukraine are under attack and Moscow has launched a campaign of instability, a U.S. defense official said Friday.

The official said Washington, which estimates that Russia has mobilized 150,000 troops near Ukraine, has not noticed any significant movement since Wednesday.

“40 to 50% are under attack. They have held tactical meetings in the last 48 hours,” the official told reporters.

Assembly points are near the border, where troops are concentrated to carry out attacks.

Moscow has amassed 125 tactical units at the gates of Ukraine, against 60 in normal times. They reached 80 in February.

The escalating clashes between pro-Russian separatists and Ukrainian government forces in the Donbass in southeastern Ukraine and the fiery declarations of the authorities in Russia and the Donbass show that the “unstable campaign has begun.”

The United States has been insisting for weeks that Russia is preparing an excuse to invade its pro-Western neighbor. Russia categorically denies this and demands a guarantee that Ukraine will not join NATO.

In 2014, Russia invaded the Crimean region of Ukraine with the support of like-minded separatists.