Heavy fighting raged between the Ukrainian military and pro-Russian separatist forces last weekend, despite a ceasefire being in place since 5 September.
The Ukrainian government has said that the West is now supplying more arms.
Nato members deny this, but around 1,300 troops from 15 countries have begun war games in Lviv, western Ukraine.
It includes the US, Nato members and former Soviet republics.
The EU has also brough in tougher sanctions as the West and Russia’s inter-imperialist rivalry continus to drive conflict.