Ukraine's President Volodymyr Zelensky accused Moscow of carrying out a "genocide" in the eastern region of Donbas, where the city of Severodonetsk is suffering an onslaught of Russian shelling, according to AFP.

In his daily televised address, Zelensky condemned Moscow's brutal assault on the Donbas -- where it has redirected its forces after having failed to capture Kyiv -- adding that its bombardment could leave the entire region "uninhabited".

"All this, including the deportation of our people and the mass killings of civilians, is an obvious policy of genocide pursued by Russia," he said.

Pro-Moscow separatist groups have since 2014 controlled parts of Donbas, but Russia now appears set on taking the whole region, according to AFP.

Russian forces are closing in on several cities, including the strategically located Severodonetsk and Lysychansk, which stand on the crucial route to Ukraine's eastern administrative center in Kramatorsk.

Three people died in attacks on those two cities, Kyiv's Deputy Defense Minister Ganna Malyar told journalists, saying that fighting in the east has reached "its maximum intensity" since Russia’s military operation on February 24.

"The situation remains difficult, because the Russian army has thrown all its forces at taking the Lugansk region," regional governor Sergiy Gaiday said in a video on Telegram.

"Extremely fierce fighting is taking place on the outskirts of Severodonetsk. They are simply destroying the city, they are shelling it every day, shelling without pause."