NATO is immediately stepping up its presence around Russian borders to reassure eastern European member states.
The move from the intergovernmental military alliance comes in an effort also aimed at increasing pressure on Russia before international talks on the Ukrainian crisis on Thursday in Geneva.
According to the Guardian, pro-Russian separatists have seized six armoured personnel carriers from the Ukrainian army.
Protesters seeking independence from Kiev have occupied at least nine government buildings in the region for more than a week.
However, this is the first time that separatist forces deep inside Ukraine have managed to seize heavy military equipment.
NATO secretary general, Anders Fogh Rasmussen, said after a meeting of alliance members that they have agreed on a package of further military measures to reinforce collective defence and demonstrate the strength of Allied solidarity.
He added that NATO will deploy more planes in the air, more ships on the water, and more readiness on the land.
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He said that military staff from Allied nations would deploy to enhance NATO's preparedness, training and exercises.
According to the report, the NATO buildup will also involve the redeployment of warships, some of them now participating in counter-piracy operations off Somalia, to the Baltic and the Mediterranean.