Ukraine's government launched talks Wednesday on decentralizing power as part of a European-backed peace plan but didn't invite its main foes, the pro-Russia insurgents who have declared independence in the east.

That deliberate oversight left it unclear whether the negotiations might help cool the tensions in the east.

In his opening remarks, acting President Oleksandr Turchynov said authorities were "ready for a dialogue" but insisted they will not talk to the pro-Russia gunmen who have seized buildings and fought government troops across eastern Ukraine.

"Let's have a dialogue, let's discuss specific proposals," Turchynov said, "But those armed people who are trying to wage a war on their own country, those who are with arms in their hands trying to dictate their will, or rather the will of another country, we will use legal procedures against them and they will face justice."

Insurgents in the east shrugged off the round-table talks as meaningless.

"We haven't received any offers to join a round table and dialogue," Denis Pushilin, an insurgent leader in Donetsk. "If the authorities in Kiev want a dialogue, they must come here. If we go to Kiev, they will arrest us."

Asked if they would be willing to take part in discussions if the round table was held in the east, Pushilin told The Associated Press that "talks with Kiev authorities could only be about one thing: the recognition of the Donetsk People's Republic."

Turchynov chaired the first in a series of round tables with spiritual leaders, lawmakers, government figures and regional officials as part of a peace plan crafted by the Organization for Security and Cooperation in Europe, a security group that also includes Russia and the United States.

Ukraine right now is deeply divided between those in the west, who want closer ties with Europe, and those in the east, who have strong traditional and language ties with Russia.

Acting Prime Minister Arseniy Yatsenyuk told participants they will be holding discussions across the country "in as many regions as possible," but didn't name any specific one.

Oleksandr Efremov, leader of the Party of Regions in the Ukrainian parliament, the support base of ousted President Viktor Yanukovych, voiced hope that the discussions will be held in the east "where things are perceived in a different way."

Efremov called on the government to withdraw its troops from the Donetsk region and urged authorities to understand that people are genuinely suspicious of the new government that came to power after Yanukovych fled to Russia in February.

The Ukrainian government, however, has said it will not stop its offensive to retake eastern cities now under the control of the separatists who declared independence Monday in the Luhansk and Donetsk regions, home to 6.6 million people.

Kiev-appointed Donetsk governor Serhiy Taruta sought to strike a reconciliatory note, urging the government among other things to refrain from calling pro-Russia protesters "terrorists" and to dismantle the protest camp on Kiev's Maidan square that led to Yanukovych's departure.

That would send a message that Kiev treats all protesters from the east and west equally, Taruta said.

The OSCE road map aims to halt fighting between government forces and pro-Russia separatists in the east and de-escalate tensions ahead of Ukraine's May 25 presidential vote. It calls on all sides to refrain from violence, offers an amnesty for those involved in the unrest and urges talks on decentralization and the status of the Russian language.

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

Even so, European officials applauded the start of the talks. The EU's enlargement commissioner, Stefan Fule, welcomed the round table on his Twitter account, voicing hope the next meeting would take place in eastern Ukraine.

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

"The government in Kiev does not want to listen to the people of Donetsk," said Denis Patkovski, a pro-Russia militiaman in the eastern city of Slovyansk. "They just come here with their guns."

Russia has strongly backed the OSCE road map while the United States, which says it's worth a try, views its prospects for success with skepticism. Sawsan Chebli, a spokeswoman for German Foreign Minister Frank-Walter Steinmeier, said Ukraine's acceptance of the round-table format was a step in the right direction, whether the pro-Russia separatists were invited or not.

The OSCE itself would not comment on the talks.

Ukraine and the West have accused Moscow of fomenting the unrest in eastern Ukraine, where insurgents declared independence for the Donetsk and Luhansk regions.

Dozens have died in the scattershot fighting across the east. On Tuesday, the Defense Ministry said six soldiers were killed and nine wounded in a rebel ambush near the city of Kramatorsk in the Donetsk region — the deadliest attack on the Ukrainian military since the offensive began last month.

Defense Ministry spokesman Bohdan Senyk said about 30 gunmen lined both sides of a road and used rocket-propelled grenades to knock out military vehicles in a battle that raged for an hour. On Wednesday morning, AP journalists saw the charred carcasses of a Ukrainian armored personnel carrier and a truck at the clash site.

Defense Minister Mykhailo Koval claimed that the insurgents were 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 said.

Russia has vehemently denied involvement.

In Donetsk, about 15 men with automatic weapons arrived at a military base Wednesday morning and demanded that the soldiers pledge allegiance to the self-proclaimed rebel Donetsk People's Republic, said Viktoria Kushnir, a spokeswoman for Ukraine's National Guard. The men blocked the base's gate with a truck but the servicemen eventually persuaded them to go, Kushnir said.

In Moscow, Sergei Naryshkin, speaker of the lower house of the 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 Ukraine's 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, apparently seeking to ease what has become the worst crisis in relations with the West since the Cold War.

The interim government had hoped that Ukraine would unite behind the new presidential election but insurgents in Luhansk and Donetsk have already said they won't allow the presidential ballot to be held.