Pro-Russian protesters listen to a speaker as they declare independence for the Luhansk region in eastern Ukraine. Pro-Russia separatists in eastern Ukraine declared independence for the Donetsk and Luhansk regions following their contentious referendum ballot. (AP Photo/Evgeniy Maloletka)

Kiev - Europe stepped up diplomatic efforts Tuesday to resolve the crisis in Ukraine, with the German foreign minister in Kiev pushing authorities and pro-Moscow rebels to come together at the negotiating table.

German Foreign Minister Frank-Walter Steinmeier's efforts came amid guarded optimism as Moscow expressed support for the “extremely important” roadmap prepared by the OSCE East-West security body to resolve the crisis.

Russia's lukewarm endorsement on Monday of weekend independence votes in the eastern provinces of Donetsk and Lugansk also allayed fears that President Vladimir Putin would move quickly to annex the territories, as he did with Crimea earlier this year.

But Moscow kept the pressure on Kiev, insisting that negotiations on regional rights must take place before a presidential vote on May 25 and accusing the pro-Western interim government of refusing “real dialogue”.

Later in the day the European Commission will host Ukraine's Prime Minister Arseniy Yatsenyuk in Brussels to offer support and discuss the next move in attempts to defuse a crisis that has brought the West's relations with Russia to their lowest point since the Cold War.

After talks with Yatsenyuk, Steinmeier said the situation in Ukraine remained “very threatening” but that he hoped progress was being made on resolving the crisis peacefully.

Calling for “a national dialogue under Ukrainian leadership,” Steinmeier said: “I hope this will create the conditions to take a step to bring back occupied territory, disarm armed groups step-by-step and reinstall the authority of the state.”

He also said the presidential election will “play a crucial role” in bringing the country out of crisis.

Steinmeier later met interim president Oleksandr Turchynov and was to travel to the southern city of Odessa.

In Moscow, the foreign ministry called on Kiev to agree to talks “in the near future, and in any case before the May 25 elections”.

It said it “expects” Ukraine's rebels to comply with the OSCE roadmap if Kiev does, calling the plan “extremely important”.

The fresh diplomatic flurry comes after rebels in eastern Ukraine appealed on Monday to join Russia following what they claimed were resounding victories in independence referendums.

Both European and US officials denounced the votes as illegal and Donetsk governor Serhiy Taruta said Tuesday the referendums were nothing more than a “social survey”.

“As for the Donetsk People's Republic, such a republic does not exist legally or politically,” he said. “There is only a dreamed-up name and nothing else.”

Moscow however said it “respects” the votes and called for talks with rebels in the industrial regions of Donetsk and Lugansk, home to seven million of Ukraine's 46 million people.

Rebel officials in Donetsk said 89 percent of voters there backed breaking away from Ukraine in Sunday's referendum, while separatists in Lugansk said 94 percent had supported independence.

The Organisation for Security and Cooperation in Europe (OSCE), which began life as a forum for East-West dialogue in the Cold War and is becoming an important player in the crisis, said Monday that Putin is “supportive” of its roadmap for Ukraine.

After a phone call between its chairman and the Russian president, the Vienna-based OSCE said the roadmap focuses on “restraint from violence, disarmament, national dialogue, and elections”.

In a statement, the Kremlin said the two had agreed on “the importance of intensifying OSCE efforts to settle the crisis”.

The OSCE has named veteran German diplomat Wolfgang Ischinger as a moderator for the talks, which they hope can take place this week involving the government, parliament and regional leaders.

Steinmeier also met Rinat Akhmetov - Ukraine's richest man and one of its most legendary powerbrokers - and he agreed to take part in talks.

“The Donbass (eastern region) can only gain happiness together with Ukraine and the referendum was not legitimate,” said Akhmetov, who has worked to mediate between the two sides.

Kiev and Western leaders have accused Moscow of backing the rebels and on Monday EU foreign ministers announced new sanctions against Russians and Crimeans involved in the crisis.

A further 13 people and two companies were listed as subject to a European Union asset freeze and visa ban.

Among them were Natalya Poklonskaya, the prosecutor of Crimea who became an Internet sensation for her good looks, and the self-styled mayor of the rebel-held Ukrainian city of Slavyansk, Vyacheslav Ponomaryov.

Canada also slapped fresh sanctions on a dozen Russian and Ukrainian separatists.

Violence has flared for weeks in eastern Ukraine as government troops carry out operations against well-armed rebels who seized several cities and towns in chaos that followed the ouster of Ukraine's pro-Russian leader Viktor Yanukovych in February.

Ukrainian officials have said 49 people have died in the Donetsk region since the start of the unrest, and deadly clashes and an inferno in Odessa killed at least 42 people earlier this month.

The rebels in Lugansk claimed their self-styled governor Valery Bolotov survived an “assassination attempt” on Tuesday after assailants opened fire on his car with automatic rifles.

“He lost a lot of blood but everything is fine now. His life is not in danger,” rebel spokesman Vasily Nikitin said, blaming Kiev for the attack.