Authorities in Kyiv have banned rallies celebrating independence in the country in fear of attacks as Russia ruled out a peace deal in the wake of an assassination.
Russia’s permanent representative to the UN Gennady Gatilov said Russia and Ukraine were close to a ceasefire as negotiations took place, but claimed that Western pressure encouraged Ukraine to walk away from any deal.
He said: "Now, I do not see any possibility for diplomatic contacts. And the more the conflict goes on, the more difficult it will be to have a diplomatic solution."
"They [Kyiv and its Western supporters] will fight until the last Ukrainian," he told the Financial Times.
Differences between the two sides remained, as particular concerns existed over flashpoints including the assassination of Darya Dugina.
Dugina was the daughter of staunch Putin ally and Russian political commentator Alexander Dugin, known as "Putin's brain."
She died when her Toyota Land Cruiser exploded west of Moscow on Saturday, August 20.
Russia claimed Ukraine was responsible for the attack and it believed Dugin may have been the intended target.
Not long before the explosion, Dugin appeared to be critical of the situation in Ukraine and said: "The Supreme Commander-in-Chief [Putin] said that we haven't really started anything yet. Now we have to start. Whether you want it or not, we’ll have to.
"Let the old regime bury its dead. A new Russian time is coming. And it’s coming irreversibly."
The father and daughter were attending a festival near Moscow and were supposed to leave in the same car together, but plans changed last minute.
Dugina said at the festival the West are a "zombie society" and was a strong supporter of the war in Ukraine.
Her father said: "My daughter Darya Dugina was brutally murdered in front of me. She was a beautiful Orthodox woman, patriot, war reporter, an expert for central TV and philosopher.
Russia's secret service, the FSB, has claimed Natalia Vovk, born in 1979 carried out the attack with her daughter before escaping across the border to Estonia.
"We only need our victory. My daughter sacrificed her young woman's life to its altar. So please, achieve it!"
Ukraine has denied any involvement and adviser to President Volodymyr Zelensky, Mykhailo Podolyak, said: "Ukraine has strongly denied any connection to the attack. Ukraine has absolutely nothing to do with this, because we are not a criminal state like Russia, or a terrorist one at that."