The European Union says the referendum in Crimea is illegal and illegitimate and its outcome will not be recognized.
European Council President Herman Van Rompuy and European Commission President Jose Manuel Barroso condemned the vote in a joint statement on Sunday.
The statement says the EU considers the referendum as contrary to the Ukrainian Constitution and international law.
It says the solution to the crisis must be based on the territorial integrity, sovereignty and independence of Ukraine.
The statement says a solution can be found only through diplomatic processes and calls for direct discussions between the governments of Ukraine and Russia.
The statement also says EU foreign ministers will decide on additional measures against Russia in a meeting in Brussels on Monday.
Meanwhile, German Chancellor Angela Merkel discussed the situation in Ukraine with Russian President Vladimir Putin over the telephone on Sunday.
German government officials say that Merkel criticized Russian troops for taking control of a gas facility in a southern Ukraine region bordering Crimea on Saturday.
Source: NHK
