The top rebel leader in eastern Ukraine says that there will be no further peace talks with Kyiv and that his fighters are advancing against Ukraine combat troops after seizing control of a long-contested airport Thursday.
Russian-backed Alexander Zakharchenko, head of the self-declared Donetsk People's Republic, said his forces would attack government troops "until we reach the borders of the Donetsk region."
Separatists currently control key territory in the Donetsk and Luhansk regions near the Russian border, after launching a rebellion nine months ago against Ukraine rule.
Zakharchenko was quoted in Russian media as saying he saw "no point" in further four-party peace talks. He told Russia's Interfax news agency that the Minsk peace talks format agreed on last year was "a mistake" that "we will not make again."
Separately, Interfax quoted rebel military official Eduard Basurin as saying more than 750 Ukrainian troops had been killed in recent days in the battle for the now-destroyed Donetsk airport.
He said more than 100 Ukraine tanks and other fighting vehicles had also been destroyed.
The rebel claims have not been independently confirmed. U.N. officials, relying on reports from the conflict zone, said they had tallied 262 deaths in the past nine days.
During a meeting with senior officials in Moscow on Friday, Russian President Vladimir Putin blamed the Ukrainian government for the latest escalation of violence in eastern Ukraine, accusing it of launching an offensive using artillery and aviation that he said had killed and wounded dozens of people, including women, children and the elderly.
Doctors Without Borders said Friday that the situation for civilians caught in the conflict zone in eastern Ukraine was "dire." The international medical charity said doctors working in hospitals close to the front line were "struggling to treat the wounded with dwindling supplies" and that heavy fighting was preventing its teams from reaching the hardest-hit areas.
The United Nations human rights agency said Friday that the death toll from the conflict in eastern Ukraine had passed 5,000. But spokesman Rupert Colville told reporters that the toll could be far higher than the official estimate of 5,086 deaths, based on data collected by U.N. human rights monitors since the beginning of hostilities in April.
In Washington on Friday, State Department spokeswoman Jen Psaki said the U.S. remained deeply concerned by the increasing violence and bloodshed in eastern Ukraine, which she said had resulted from a surge in separatist attacks against the cease-fire line in what appeared to be a general offensive. She said the separatists had carried out 1,000 attacks since early December.
Psaki said Russia is actively supporting the separatists by supplying them with heavy weaponry and vehicles, including tanks, armored personnel carriers and heavy artillery, as well as providing military personnel for exercising ongoing tactical support.
She again called on Russia to stop the flow of heavy weapons, fighters and advisers; to restore Ukraine’s control along its side of the international border; and to allow monitoring along both sides of the border by the Organization for Security and Cooperation in Europe.