KIEV, Ukraine >> The Ukrainian government reluctantly agreed to launch talks on decentralizing power Wednesday as part of a European-backed peace plan, but with no invitation for the pro-Russian insurgents who have declared independence in two eastern regions it was unclear what the negotiations might hope to accomplish.

Ukraine’s prime minister, Arseniy Yatsenyuk, was to chair the first in a series of round tables set to include national lawmakers, government figures and regional officials as part of a peace plan drafted by the Organization for Security and Cooperation in Europe, a trans-Atlantic security and rights group that includes Russia and the United States. 

But Yatsenyuk gave no indication that he would invite his foes into the process, as the OSCE plan calls for. And even as he launched the talks he was dismissive of them, thanking the OSCE for its efforts but saying Ukraine has its own plan to end the crisis. In a speech in Brussels on Tuesday, he gave no details of that plan.

Acting Ukrainian President Olexandr Turchynov said the talks would involve “regional elites.” Also expected were former Ukrainian presidents, officials and lawmakers. But, Turchynov said, “the government will act against those who are terrorizing the region with arms in hand in line with the law, by continuing an anti-terrorist operation against them.” 

Many insurgents in the east shrugged off the round table as meaningless.

“The government in Kiev does not want to listen to the people of Donetsk,” said Denis Patkovski, a member of pro-Russian militia in Slovyansk, which has seen some of the most intense fighting in recent weeks. “They just come here with their guns.”

Even so, European officials applauded the start of the talks. The EU’s enlargement commissioner, Stefan Fule, welcomed the launch of the round table on his Twitter account, voicing hope that the next such meeting will take place in the east.

Russia has strongly backed the OSCE road map. The United States, while saying it’s worth a try, views its prospects for success with skepticism.

Ukraine and the West have accused Moscow of fomenting the unrest in eastern Ukraine, where insurgents have seized administrative buildings, fought government forces and declared independence for the Donetsk and Luhansk regions after a jury-rigged vote last weekend that Ukraine and Western powers called a sham.

Ukrainian forces have mounted a scatter-shot offensive against the insurgents, and dozens have died in the fighting across the east. On Tuesday, the Defense Ministry said six soldiers were killed by rebels who ambushed a convoy near the city of Kramatorsk in the Donetsk region — the deadliest attack the Ukrainian military has seen since it began last month to try to uproot the mutiny.

Defense Ministry spokesman Bohdan Senyk said about 30 gunmen positioned themselves on both sides of the road and used rocket-propelled grenades to knock out the military vehicles during a battle that raged for about one hour. He said nine servicemen were wounded.

On Wednesday morning, AP journalists saw charred carcasses of a Ukrainian armored personnel carrier and a truck at the site of the clash.

Defense Minister Mykhailo Koval claimed that the insurgents are being aided by Russian servicemen: “Russia has waged an undeclared new-generation war in Ukraine. The neighboring country has unleashed a war using units of terrorists and saboteurs.” 

He added that some of the men had besieged a Ukrainian military base in the east openly introduced themselves as officers of Russia’s 45th Airborne Regiment. 

Russia has vehemently denied involvement.

On Wednesday morning, about 15 men armed with automatic weapons arrived at a military base in the city of Donetsk and demanded that the soldiers pledge allegiance to the self-proclaimed Donetsk People’s Republic, said Viktoria Kushnir, a spokeswoman of Ukraine’s National Guard. The men blocked the gate of the base with a truck for half an hour,but after a lengthy conversation servicemen persuaded the armed men to go, Kushnir said.

The OSCE plan calls on all sides to refrain from violence, an amnesty for those involved in the unrest, and talks on decentralization and the status of the Russian language. It envisages a quick launch of high-level round tables across the country, bringing together lawmakers and representatives of the central government and the regions.

Ukrainian Foreign Ministry spokesman Yevhen Perebiynis lamented that the OSCE plan does not specifically oblige Russia to do anything.

In Moscow, Sergei Naryshkin, the speaker of the lower house of Russian parliament, said Wednesday that the Ukrainian authorities’ refusal to speak to their foes and the continuing military operation in the east will undermine the legitimacy of the May 25 presidential vote.

But in an important change, he added that the failure to hold it would be even worse. 

“It’s hard to imagine that this election could be fully legitimate,” Naryshkin said on Rossiya 24 television. “But it’s obvious that the failure to hold the election would lead to an even sadder situation, so it’s necessary to choose the lesser evil.”

Moscow had previously called for postponing Ukraine’s presidential vote, saying it must be preceded by a constitutional reform that would turn Ukraine into a federation. It has recently taken a more conciliatory stance, reflecting an apparent desire to ease what has become the worst crisis in relations with the West since the Cold War.

It’s unclear how much sway Russia has over the insurgents in the east, who proceeded with their referendum last weekend despite Russia’s opposition. The insurgents in Luhansk have already said they won’t allow balloting on May 25, and the leader of pro-Russian activists in Donetsk, Denis Pushilin, said they will use unspecified “means and methods” to prevent the vote from happening.

Former Prime Minister Yulia Tymoshenko, who is running for president in the May 25 election, criticized the authorities for failing to engage their opponents and urged the government to move the round tables from Kiev to Donetsk, the main city in the rebellious east.

But that wouldn’t be enough for many of the insurgents.

“How can there be any relationship with us when they bring their weapons?” asked militiaman Sergei Davidov. “They’ve simply got to pack up and leave and nothing more will come of it.”

Yuras Karmanau in Donetsk, Ukraine, Srdjan Ndelejkovic and Alexander Zemlianichenko in Slovyansk, Ukraine and Vladimir Isachenkov in Moscow contributed to this report.