Pro-Russian insurgents in Ukraine’s Donetsk region declared independence Monday and asked to join Russia – a day after holding a hastily arranged vote on separatism that Ukraine’s interim government and the West have declared a sham.

Organizers said about 90 percent 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.

There was no immediate response from the Kremlin to Monday’s statement issued by one of the insurgent leaders, Denish Pushilin. But the Kremlin suggested earlier it had no intention of immediately annexing the two regions.

Ukraine’s central government and the West strongly criticized Sunday’s hastily arranged, unofficial ballot in the Donetsk and Luhansk regions- which together have 6.5 million people – as a violation of international law. They accuse 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.

In Moscow, Russian President Vladimir Putin’s office urged the Ukrainian government to engage in talks with representatives of eastern Ukraine that could be brokered by the Organization for Security and Cooperation in Europe. The cautious stance – which contrasted with Russia’s quick annexation of Crimea after a separatist vote there – appears to reflect Putin’s hope of negotiating a 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 civilized way without any throwbacks to violence through a dialogue between representatives of Kiev, Donetsk and Luhansk,” the statement said.