The Ukrainian Defense Ministry says the offensive was in its most active phase, Moscow said it would continue until all of its objectives had been met.

The city of seven Donetsk is almost encircled by Russian forces.

Neighboring towns and villages are being heavily shelled as well.

Let's take you live to Vienna in Austria were joined by Nikolai Petrov, a senior research fellow on the Russia and Eurasia program at Chatham House in London and professor at the High School of Economics in Moscow.

Good to have you with us.

For your perspective, Nicolai, are we in a new phase of the war?

I think that Russian military plan did change and now we're switching to the war of attrition uh, position in war when uh Russian leadership is waiting for the negative consequences of the war directly being failed by Ukrainians in order to change their public mind and make it easier to make any concessions.

But having said for weeks that the Russians were on the back foot, does it seem that they now definitely have the upper hand in Donbas?

I think that they are closer to the task proclaimed to restore borders of self proclaimed Donetsk and Luhansk Republics to administrative borders of proper Ukrainian regions.

But what I think is even more important is the fact that Russian troops now do control the coast of the sea of Azov and part of the coast of the Black Sea cutting off Ukraine from the sea.

How are Ukrainians in the east, getting their weapons?

How are the supply lines?

Well, I think it works.

It works well.

But one should not wait for any immediate changes.

And if Russian troops will switch to defensive in order to keep those territories which are already under their control, I think it will be very complicated for the Ukrainian army to take these territories back.

Because what are the tactics of the Russians in Donbas?

Is it the sort of usual playbook of encircling towns and then bombarding them?

Well, I think the situation in Donbas does show how complicated it is to get control over territories if the other side is well prepared for the defense so far.

Russian army is trying to get all territories which the parts of Daniel's can't Lugansk regions of Ukraine.

But even this task is hardly possible.

Do you believe that ultimately President Zelensky and Ukraine will have to give up part of all of the Donbass region?

I'm afraid that the well gaining back control over all territories of Ukraine will take a lot of time and it's hardly probable that it will happen in a short while.

That's why I think that ceasefire which can help to stop this huge, cruel and very painful war will be achieved and later, perhaps not even this year, but later, Ukraine will manage to restore its territorial integrity.

Nikolai Petrov, thank you for joining us with your thoughts, your analysis from Vienna.