Ukrainian President Volodymyr Zelenskiy said on Tuesday Russia must stop bombing Ukrainian cities before meaningful talks on a ceasefire could start, as a first round of negotiations this week had yielded scant progress.

Speaking in an interview in a heavily guarded government compound, Zelenskiy urged NATO members to impose a no fly zone to stop the Russian air force, saying this would be a preventative measure and not meant to drag the alliance into war with Russia.

Zelenskiy, who has refused offers to leave the Ukrainian capital as Russian forces advanced, also said Ukraine would demand legally binding security guarantees if NATO shut the door on Ukraine's membership prospects.

Setting out his conditions for further talks with Russia, Zelenskiy told Reuters and CNN in a joint interview: "It's necessary to at least stop bombing people, just stop the bombing and then sit down at the negotiating table."

Just as he was speaking, news emerged that a Russian missile had struck a TV tower near a Holocaust memorial site in the Ukrainian capital, killing at least five people. Earlier on Tuesday, missiles struck the heart of the eastern city of Kharkiv.

Ukraine has received weapons shipments from NATO members to help withstand a full-scale military invasion unleashed by Russian forces last week, while the West has also introduced swingeing sanctions on the Russian economy.

But Zelenskiy has urged the international community to do more, including imposing a no fly zone.

"This is not about dragging NATO countries into war. The truth is everyone has long since been dragged into war and definitely not by Ukraine, but by Russia - a large-scale war is going on," Zelenskiy said.

He said, however, that U.S. President Joe Biden had personally conveyed to him that now was not the time to introduce such a measure.

Ukraine has pressed NATO to accelerate its entry, a move fiercely opposed by Russia and cited as one of Moscow's reasons for launching its campaign.

"Our partners, if they are not ready to take Ukraine into NATO ... because Russia does not want Ukraine to be in NATO, should work out common security guarantees for Ukraine," Zelenskiy said.

"This means that we have our territorial integrity, that our borders are protected, we have special relations with all our neighbours, we are completely safe, and the guarantors that give us security, they guarantee this legally."