"This is an EU-wide and EU coordinated exercise," Peter Stano, a foreign affairs spokesman for the bloc, told AFP.
EU nations on Friday began calling in Russian envoys after Putin formally claimed four regions of Ukraine occupied by his troops since the war.
Belgium on Friday summoned the Russian ambassador, and Italy and Austria were among those that have since followed suit.
EU leaders have vowed that they "will never recognise the “annexation" carried out by Moscow and the bloc is readying fresh sanctions.
EU diplomats were trying to overcome objections from Hungary to agree a new package of economic punishment that would include moves to impose a price cap on Russian oil sold around the world.
The bloc has already imposed seven waves of unprecedented sanctions on Russia and supplied military aid to Ukraine worth billions of dollars.