EU foreign ministers meeting in Brussels have imposed visa bans and asset freezes on a further 13 individuals accused of being responsible for de-stabilising eastern Ukraine.

The EU imposed sanctions on 13 Russian and pro-Russian individuals in the east of Ukraine following yesterday's referendums, which Europe and the West have called illegal and illegitimate.

For the first time the EU has placed sanctions on two energy companies in Crimea, the Ukrainian peninsula annexed by Russia in March.

As expected, Europe has once again stopped short of announcing full economic and trade sanctions against Russia, although there have been warnings from France, Germany and the UK that if Moscow attempts to disrupt the presidential elections on 25 May tougher sanctions could follow.

Foreign ministers also heard from the current chair of the monitoring body, the OSCE, who noted that while Moscow said it had respected the result of the referendums, it had not formally recognised the outcome.

Didier Burkhalter told reporters afterwards that there were signals from Moscow that it would countenance a dialogue with Kiev, but one which also included interlocutors from pro-Russian separatists in eastern Ukraine.

One of the leaders of eastern Ukraine's separatist rebellion said today that joining the Russian Federation would probably be an appropriate step following the referendums.

"Joining the Russian Federation would probably be an appropriate step," Roman Lyagin, head of the Donetsk's self-styled electoral commission,  told a news conference. 

Earlier, Ukraine's interim president Oleksander Turchynov accused Russia of working to overthrow legitimate state power in Ukraine after pro-Russian rebels declared victory in rebel referendums on self-rule in eastern regions.

The polls were described as "farce without legal basis" by Mr Turchynov.

"The farce that terrorist separatists call a referendum is nothing more than propaganda to cover up murders, kidnappings, violence and other serious crimes," Mr Turchynov told Ukraine's parliament.

Russia said it respected the outcome of the referendums, in which separatists in the industrial Donetsk region claimed 90% support; final results for the Luhansk region showed 96.2% in favour of self-rule.

Russia said the results should be implemented peacefully, but did not say what further action it might take.

Russian Foreign Minister Sergei Lavrov said this morning there were no new international talks planned for now on Ukraine.

He said progress in de-escalating the crisis was possible only if the rival sides in Ukraine held direct talks.