British Foreign Secretary William Hague has said there is no doubt that Moscow is behind the destabilization of eastern Ukraine.

"There can't really be any real doubt that this is something that has been planned and brought about by Russia," he said, adding that Russia was deliberately "violating the independence and sovereignty of Ukraine."

Speaking on Monday at a meeting of EU foreign ministers in Luxemburg to discuss the crisis, Hague said the events had all the hallmarks of Russia's earlier actions to seize Crimea from Ukraine: " It has all the appearance of a further gross, deliberate, premeditated violation of the independence and sovereignty of Ukraine."

The UK foreign secretary dismissed denials of Russian involvement and called for further sanctions against Moscow.

"I don't think denials of Russian involvement have a shred of credibility," he said.

According to him, Russia's behavior towards Ukraine is an evident threat to the forthcoming elections in Ukraine on May 25.

Besides, Hague said he would be arguing for the EU to take further measures to sanction Russia for its actions. A so-called " third phase" of EU sanctions is expected to include restrictions on trade and finance with Russia, potentially with wide-reaching repercussions for the Russian and EU economies.