Pro-Russia insurgents in Ukraine's Donetsk region declared independence on Monday and asked to join Russia - a day after holding a hastily arranged vote on separatism that Ukraine's government and its western allies said violated international law.
The Kremlin had no immediate response Monday to the annexation request, but issued a statement earlier in the day that urged Ukraine's government in Kiev to hold talks with the pro-Russia insurgents in the east.
Organisers said about 90% of those who cast ballots Sunday in Donetsk and the neighboring Luhansk region backed sovereignty for the sprawling areas that lie along Russia's border and form Ukraine's industrial heartland. Donetsk has about 4.4 million people and Luhansk has 2.2 million.
Insurgents in the Luhansk region stopped short of mimicking the move made by their kin in Donetsk, but spokesman Vasily Nikitin said the Luhansk region will not vote in Ukraine's May 25 presidential election.
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Ukraine's central government and the West have completely rejected Sunday's insurgent vote and accused Moscow of fomenting weeks of unrest in eastern Ukraine in a possible attempt to grab more land after annexing Crimea in March - accusations that Russia has denied.
"The farce, which terrorists call the referendum, will have no legal consequences except the criminal responsibility for its organizers," Ukraine's acting President Oleksandr Turchynov said in a statement.
The interim government in Kiev had been hoping the presidential vote would unify the country behind a new, democratically chosen leadership. Ukraine's crisis could grow even worse if regions start rejecting the presidential vote.
In Moscow, Russian President Vladimir Putin's office voiced hope that the Organization for Security and Cooperation in Europe could help broker talks between the central government and the two provinces.
The cautious stance - which contrasted with Russia's quick annexation of Crimea after a separatist vote there - appeared to show Russia favoring a negotiated solution to what has become the worst crisis between Russia and the West since the Cold War.
"The practical implementation of the referendum results should proceed in a civilised way without any throwbacks to violence through a dialogue between representatives of Kiev, Donetsk and Luhansk," the Kremlin said.
The pro-Russia insurgents who organised Sunday's vote claimed 89% of those who cast ballots in the Donetsk region and about 96% of those who turned out in the neighboring Luhansk region voted for sovereignty. The insurgents said turnout topped 70%, but with no international election monitors around it was impossible to confirm such claims.
Turnout was brisk at some polling stations visited by AP journalists. At one polling station at a school in Donetsk, all the voting slips that could be seen in the transparent ballot boxes showed that self-rule had been selected.
Most opponents of sovereignty likely stayed away from the polls rather than risk attracting attention to themselves, but there were no obvious signs of outright intimidation by the armed pro-Russia forces who have captured government buildings across the east.
Surveys by polling companies have indicated that a significant majority of people in Ukraine want to keep their country united.
Swiss President Didier Burkhalter, whose country currently chairs the OSCE, met with Putin last week to propose a road map for settling the Ukrainian crisis and outlined some of that plan Monday in Brussels.
"We have seen in Moscow that there is openness for a dialogue," Burkhalter said.
The OSCE plan urges all sides to refrain from violence and calls for an immediate adoption of an amnesty law. It also envisages a comprehensive national dialogue focusing on decentralization and the status of the Russian language. Burkhalter emphasized that it would be up to Ukraine to figure out how to set up the talks.
He said Ukraine has accepted a proposal to nominate Ambassador Wolfgang Ischinger of Germany as the OSCE co-moderator for the talks.
Dutch Foreign Minister Frans Timmermans welcomed the plan, saying "the OSCE offers us the best opportunity to try to get a diplomatic solution to the situation".
Maintaining its pressure on Moscow, the European Union's foreign ministers added 13 people and two firms Monday to their visa ban and asset freeze list over Ukraine, according to two officials who spoke on condition of anonymity because the measure had yet to be officially announced.
The US and the EU, which have slapped travel bans and asset freezes on members of Putin's entourage after Russia's annexation of Crimea, have warned they could target entire sectors of the Russian economy if Moscow tries to derail Ukraine's May 25 presidential vote.
The Kremlin, meanwhile, criticized Ukrainian authorities for trying to thwart the balloting by using weapons against civilians. It noted the reported high turnout in the vote and voiced respect for its results.
The Russian Foreign Ministry said in a statement published Monday that the referendum "convincingly shows the true mood of citizens" in east Ukraine, but like the Kremlin said that the crisis must be resolved with dialogue between the Ukrainian sides.
Russian Foreign Minister Sergey Lavrov said Moscow sees no need for another four-way meeting between Russia, the United States, the EU and Ukraine following their talks in Geneva last month, saying that the Ukrainian authorities should now focus holding a dialogue with the east.
He accused Washington and Kiev's government of stonewalling the OSCE plan and warned that efforts to defuse Ukraine's crisis wouldn't be successful without "engaging opponents of the regime in a direct dialogue."
Last week Putin had urged the organizers to postpone the balloting in an apparent attempt to distance himself from the insurgents, who have seized government buildings and clashed with government troops and police. Dozens have been reported killed since Ukrainian forces began trying to retake some eastern cities.
Sunday's voting appeared mostly peaceful but armed men stopped the voting and took control of the town hall in Krasnoarmeisk, then opened fire on the crowd outside. They identified themselves as Ukrainian national guards but the interior ministry said they were not. Two deaths were reported.
Turchynov and Ukraine's caretaker government came to power in February following the ouster of Kremlin-friendly President Viktor Yanukovych after months of protests in Kiev. Moscow and many in Ukraine's east have accused the new government of intending to trample the rights of Russian-speakers.