Ukrainian President Volodymyr Zelensky said Tuesday on state television that amid the Russian invasion, Ukraine will become "big Israel", with security being the top priority for the country over the next 10 years.
In an interview with Ukrainian journalists broadcast on national television, Zelensky also said that "Ukraine had no option but to negotiate with Russia to end fighting," but him and Russian President Vladimir Putin might not talk in person.
Zelensky was speaking after accusing Russian troops of carrying out extra-judicial killings in the town of Bucha west of the Ukrainian capital, Kyiv.
"All of us, including myself, will perceive even the possibility of negotiations as a challenge," Zelensky said. "The challenge is internal, first of all, one's own, human challenge. Then, when you pull yourself together, and you have to do it, I think that we have no other choice."
He said the events in Bucha were unforgivable and signaled that Moscow should recognize what its troops were alleged to have done.
The Russian news agency Interfax cited a deputy Russian foreign minister as saying talks between the two sides were continuing via video link.
Meanwhile, satellite images released on Monday appear to refute Russian assertions that dead bodies in civilian clothing found in Bucha had appeared there after Russian forces retreated from the devastated Ukrainian town.
Former Russian President Dmitry Medvedev said the reports of civilian killings in Bucha were "fakes" aimed at discrediting Russia. Moscow said it would present "empirical evidence" to a meeting of the United Nations Security Council on Tuesday proving its forces were not involved.
Mid-March satellite imagery of a Bucha street showed several bodies of civilians lying dead in or just off the roadway where Ukrainian officials recently said they found multiple corpses after Russian troops withdrew.
Russia's Defense Ministry also denied responsibility, saying that all its units "withdrew completely from Bucha as early as March 30," while the Kremlin has dismissed the graphic images emerging from the town as "fakes" concocted by Ukraine.
That claim was repeated at the United Nations on Monday, where Moscow's envoy Vassily Nebenzia reiterated at a press conference the corpses pictured in Bucha were not there before Russian troops left the city.
"Suddenly they appear on the streets lying on the road, one by one, left and right, some of them are moving, some of them showing the signs of life," he said, claiming the scenes were "arranged by the Ukrainian information, information warfare machine."
But Maxar satellite images dated March 19 and March 21 show that multiple bodies were on Bucha's Yablonska street at that time.
And according to the Times analysis, Maxar images show dark objects of similar size to human bodies appearing on the street between March 9 and 11.
Many of the bodies pictured in the satellite images appeared in the precise position on the ground as seen in video footage from the same street filmed by a Ukrainian local council member, and in photographs by international news outlets.