At least five people were killed in fighting between pro-Russian militiamen and Ukrainian forces near Donetsk.

A day after Ukrainian troops suffered their single heaviest loss of life against pro-Russian separatists in an ambush attack, Ukraine’s interim leaders began discussions on national unity in Kiev.

A day after Ukrainian troops suffered their single heaviest loss of life against pro-Russian separatists in an ambush attack, Ukraine’s interim leaders began discussions on national unity in Kiev.

The first round of talks on Ukrainian national unity descended into grandstanding and accusations Wednesday, offering no sign of a diplomatic breakthrough in the region’s tensest standoff since the Cold War.

Although strongly backed by the West and ostensibly by Russia, the negotiations as they are currently cast are unlikely to have an immediate effect on the escalating violence in eastern Ukraine. During the talks, Prime Minister Arseniy Yatsenyuk pressed an offer to give more powers to Ukraine’s regions. But he and other members of the interim government in Kiev have ruled out a seat at the negotiating table for the pro-Russian separatists who have captured administrative buildings and are confronting Ukrainian military forces in deadly skirmishes in the east.

“We will conduct a dialogue only with all those who do not shoot and do not kill citizens,” he said.

Yet several politicians from the east who are distrustful of the new government came to Kiev, engaging with the interim leaders, two former presidents and other representatives of Ukraine’s religious and business communities. In a twist that seemed to take several speakers by surprise, the talks were broadcast live on the parliament’s television channel, lending an air of political theater to the proceedings.

The talks, more than anything else, appeared to lay bare the gulf between those Ukrainians who support the interim government and those who do not. Pro-Kiev representatives often seemed to argue that the unrest and distrust throughout the east were strictly engineered by Russian operatives. Angry easterners, meanwhile, suggested that such comments only proved their point that officials in Kiev were out of touch with Russian speakers in the east who are deeply skeptical of the pro-Western uprising that ushered in the interim government in February.

During the talks, Inna Bohoslovska, a politician from the eastern city of Kharkiv, said some in her region cannot even understand Ukrainian-language news broadcasts or Ukrainian-dubbed movies. In what appeared to be a reference to the absence of separatists at the table, she said officials in Kiev should have invited “everyone” to the talks.

“Are you suggesting we should invite separatists, Russians here?” said former Ukrainian president Leonid Kravchuk, a supporter of the interim government.

“They are also Ukrainians!” she countered.

After 21 / 2 hours, the talks broke up with agreement in principle to hold another round in the coming days in Donetsk, a hot spot in the east where separatists have seized key buildings. But Kravchuk, citing security concerns, sounded dubious.

“We don’t want to lose half the members of the roundtable on the way home,” he said.

It remained doubtful, however, that the pro-Russian separatists would join the talks even if asked. Some separatist leaders in Slovyansk and Luhansk have refused to talk with the Kiev authorities, viewing them as illegitimate. Others said they have not been approached with an offer.

Nevertheless, the talks on Wednesday amounted to the tenuous start of a process of negotiations being conducted under the auspices of the Organization for Security and Cooperation in Europe, a Vienna-based body that includes European powers as well as the United States, Russia and others. An OSCE peace plan calls for both sides to end the violence. In return for amnesty, the separatists would have to lay down their arms. Meanwhile, both sides would engage in negotiations on explosive topics including decentralization of power and the legal status of the Russian language.

On Wednesday, however, most of the issues were touched on only with a broad brush, and some — such as an amnesty — not at all.

In Moscow, officials appeared to soften their stance, at least publicly. Russian Foreign Minister Sergei Lavrov warned in an interview with Bloomberg Television that Ukraine was closer than ever to civil war and said that any attempt by its government to join NATO would be “an issue” for Moscow.

But he also said that Russia has “no intention” of sending troops into eastern Ukraine, despite Western fears that Moscow will invade after Ukraine’s presidential and mayoral elections, set for May 25.

Lavrov spoke at length about Russia’s deep historical and “psychological” ties to Ukraine, even saying that Russians “do not consider [themselves] foreigners” there. But he refused to respond directly to a question about whether Russia would annex more Ukrainian territory, calling the query “hypothetical.” Russia annexed Crimea, an autonomous Ukrainian region, in March after a hastily arranged referendum there.

At the same time, the situation in eastern Ukraine remained tense. Armed men entered the Novokramatorsky machinery plant in Kramatorsk and made off with a heavy construction vehicle, and the pro-Ukrainian head of a school was abducted and later released. Masked gunmen also abducted the head of the district’s voting commission.

A day earlier, Ukraine’s Defense Ministry said, six soldiers were killed near Kramatorsk in one of the bloodiest clashes of the conflict. The ministry also said that a militant was killed and four others were wounded in the fighting. Local news media had reported that a seventh Ukrainian soldier died of his wounds, but the reports have not been confirmed.

In Kiev, analysts conceded that it was hard to imagine the separatists surrendering their arms without a seat at the negotiating table. Yet resistance to offering them a seat appeared strong.

“We’re ready to discuss questions, but for those who are armed and are trying to fight against their own country, to those who are holding guns and trying to dictate their own will, or, better said, the will of another country, for those we will have other methods,” Oleksandr Turchynov, the acting Ukrainian president, said at the start of the talks.

Kunkle reported from Donetsk. Abigail Hauslohner in Moscow contributed to this report.