Ukrainian politicians and civil groups gathered on Wednesday for talks on how to quell a pro-Russian rebellion in the east, but Kiev's refusal to let separatists take part cast doubt on whether the meeting could defuse the crisis.

A Ukrainian Interior Ministry officer mans a checkpoint outside the eastern Ukrainian village of Bylbasivka May 14, 2014.

The talks come at a tense moment for Kiev. On Tuesday, seven soldiers were killed in an ambush near the eastern city of Kramatorsk, the deadliest attack on security forces since they were sent to tackle the uprising in April.

Voters in the eastern regions of Donetsk and Luhansk backed self-rule in two referendums held on Sunday despite protestations from Kiev, which sees Russia's hand behind the rebellion and denounced the votes as illegal.

After the vote rebel leaders in Donetsk and Luhansk called for their regions to become part of Russia although this call has not been taken up by Moscow.

Wednesday's talks brought together ministers, political party leaders, candidates for a May 25 presidential election, business representatives and local government officials.

Participants are expected to explore methods of devolving power to allow greater local autonomy which Kiev hopes will address disaffection in eastern Ukraine.

However, Kiev has excluded rebels, whom it terms as "terrorists", from the round table discussions, drawing criticism from abroad. Moscow has said there should be direct talks between separatists and Kiev.

"We are ready for talks with everyone who has legitimate political goals and is ready to pursue them by legal means, with those who do not have blood on their hands," acting President Oleksander Turchinov and Prime Minister Arseny Yatseniuk said in a joint statement.

CLASH WITH OPPOSITION

Among those to express hope in the talks was German Chancellor Angela Merkel, who said the more representatives were present, the better. The unrest in Ukraine and Russia's annexation of Crimea have contributed to the worst East-West crisis since the 1991 collapse of the Soviet Union.

In Slaviansk on Wednesday, Stella Khorosheva, spokeswoman for the rebels, said they had no official position on the talks.

"But Kiev is calling us terrorists and extremists which are all serious accusations that could have major legal consequences. We are trying to liberate our country and we are not terrorists," Khorosheva said.

There have been no public negotiations between separatists and the government since the crisis began in early April.

"There is no reason to expect any concrete decision (from the talks)," independent analyst Volodymyr Fesenko said.

"If there are not people in authority from the east at these talks this round-table will lose all sense."

The stage also seemed set for a clash between the interim leadership, which took power after the ousting of Moscow-backed president Viktor Yanukovich in February, and the opposition.

Opposition politicians, many from the rump Party of Regions of Yanukovich, say the Ukrainian authorities are only inflaming the situation in the east by deploying armed forces there.

In a statement ahead of the round-table, the parliamentary faction of the Regions called for an end to military action in the east and "a halt to bloodshed and mass killing of people."

Ukraine's authorities are hoping to push a de-centralization plan under which greater powers would devolve to the regions and allow them to hold back a portion of taxes for direct use in improving infrastructure and conditions for local businesses.

They hope this will defuse local grievances - and cut some of the ground from under the separatists.

But the plan's architects are keen that they do not allow discussion of 'federalization' - an idea pushed by Russia and the separatists - which they fear would lead to too-great autonomy and weaken the grip of the central government.