KYIV (NYTIMES) - After weeks of trying to hammer out a peace deal, negotiators for Russia and Ukraine appear further apart than at any other point in the nearly three-month-long war, with the talks having collapsed in a thicket of public recriminations.

Mr Vladimir Medinsky, head of President Vladimir Putin's delegation, claims that Russia has still not received a response to a draft peace agreement that it submitted to Ukraine on April 15.

Mr Rustem Umerov, a top Ukrainian negotiator, responded by saying that Russia was operating with "fakes and lies."

"We are defending ourselves," Mr Umerov said in an interview. "If Russia wants to get out, they can get out to their borders even today. But they are not doing it."

On Tuesday (May 17), both sides further played down the prospects of a deal. Another Ukrainian negotiator, Mr Mykhailo Podolyak, issued a statement saying that the talks were "on pause" and that given Russia's faltering offensive, the Kremlin "will not achieve any goals."

And Mr Andrei Rudenko, a Russian deputy foreign minister, told reporters that "Ukraine has practically withdrawn from the negotiating process," the Interfax news agency reported.

The impasse stems primarily from Russia's insistence on maintaining control of large swaths of Ukrainian territory, and Mr Putin's apparent determination to push ahead with his offensive.

But another factor is an emboldened Ukraine: Its successes on the battlefield, combined with anger over Russian atrocities, have the Ukrainian public less willing to accept a negotiated peace that would keep a significant amount of land in Russian hands.

Ukraine is further bolstered by an extraordinary influx of weapons and aid from the West. The US Senate is expected to approve a US$40 billion (S$55.38 billion) package of military and economic aid for Ukraine as early as Wednesday.

"Now that we feel more confident in the fight, our position in the negotiations is also getting tougher," Ukraine's foreign minister, Mr Dmytro Kuleba, told German newspaper Die Welt in an interview published last week. "The real problem is that Russia does not show the desire to participate in real and substantive negotiations."

In Russia, officials say that it is the Ukrainians that are intransigent and that they are being egged on to continue the fight by Western leaders.

Prime Minister Kaja Kallas of Estonia, for instance, said the West needed to push for a military defeat of Mr Putin rather than "a peace that allows aggression to pay off."

Both sides have stuck to talking points that advanced their own agenda. Mr Medinsky, in his first interview with a Western news outlet since the beginning of the war, claimed that Ukrainian negotiators had previously agreed to much of the draft deal that he said Russia had submitted to Ukraine last month.

"But they probably represent that part of the Ukrainian elite that is most interested in reaching a peace agreement," Mr Medinsky said, referring to the negotiators. "And there is probably another part of the elite that doesn't want peace and that draws direct financial and political benefit from a continuation of the war."

Discussions among mid-level negotiators have continued for weeks. But in a sign of how far off a peace agreement now appears to be to both sides, negotiators were focused on more granular issues like prisoner exchanges and humanitarian efforts, and on lifting Russia's blockade of Ukraine's Black Sea ports.

Still, the fact that some talks have been taking place at all shows that a negotiated end to the war is not entirely out of reach.

On Monday, after weeks of negotiations that both sides worked to keep secret, Ukraine agreed to surrender its fighters sheltering in a steel plant in the port city of Mariupol. Officials said they expected the fighters to be freed by Russia in a prisoner exchange.

Mr Medinsky, a conservative former culture minister whom Mr Putin appointed as his chief Ukraine negotiator in February, said that Russia remained interested in a peace deal with Ukraine that would make it a "neutral and peaceful country, friendly to its neighbours."

He said Russia wanted peace under an "Austrian model" - Austria belongs to the European Union but not to Nato - that would allow Ukraine to remain an independent country. He would not specify whether Russia was prepared to cede any territory.

He evoked past conflicts between the American North and South, Germany and Austria, and England and Scotland as historical evidence that today's enmity between Russia and Ukraine would eventually end.

"Sooner or later, peace, mutual interests, harmony and mutually beneficial cohabitation is found, in various forms," he said. "Our task as negotiators is to make this come sooner, if possible."

Mr Medinsky's comments sounded a more conciliatory note than the hardline rhetoric increasingly heard on Russian state television, a sign that the Kremlin wanted to keep its options open, with its military struggling on the battlefield.

But Mr Medinsky offered few details of the progress of the talks.