Russia has concentrated more than 100,000 troops on Ukraine’s border and in annexed Crimea, according to the EU’s top diplomat Josep Borrell.
Mr Borrell revealed growing tensions in the region after EU foreign ministers were briefed by Ukraine’s foreign minister.
“The risk of further escalation is evident,” Mr Borrell said on Tuesday, (AEDT) but declined to give a source for the figure, which he first said was more than 150,000 before it was revised down by his services.
“It is the highest military deployment of the Russian army on the Ukrainian borders ever. It’s clear that it’s a matter of concern when you deploy a lot of troops,” he said.
Mr Borrell said no new economic sanctions or expulsions of Russian diplomats were planned for the time being, despite saying the military build-up on Ukraine’s borders was the largest ever.
In Washington, the Pentagon said the Russian military build-up was larger than that in 2014 and it was not clear that it was for training purposes.
A US official, speaking on the condition of anonymity, said the Russian build-up numbered in the tens of thousands but was not aware of intelligence that pointed to more than 150,000 Russian troops.
Ukrainian Foreign Minister Dmytro Kuleba, after addressing EU foreign ministers, called on the EU to impose new sanctions on Russia.
Tensions between Moscow and Kyiv have been rising amid the military build-up and clashes in eastern Ukraine between the army and pro-Russian separatists.