French President Francois Hollande said Europe's leaders would cancel a June summit with Russia and decide fresh sanctions against Russian figures as he arrived Thursday for a European Union summit.

Saying events in Ukraine and Crimea were "unacceptable", the French leader said "sanctions will be decided against a certain number of figures, regarding their personal situation or their financial assets".

"There was to have been a meeting between the EU and Russia but it cannot take place in these conditions," he said, referring to a planned June summit.

"We must also plan other sanctions if there is an escalation," he added.

With the EU's 28 nations divided over whether to ratchet up the bloc's response by agreeing economic sanctions, Hollande said that "even if not decided today, economic sanctions must be discussed, prepared".