However, he added Russian troops had damaged a bridge which helped humanitarian goods get delivered to the region and that civilians have been evacuated.
Mr Haidai also said Russia has been “deliberately destroying a multidisciplinary hospital”.
He wrote: “The seven-story building has in fact already become a four-story building.
“There are three doctors working there who say they will stay until the last.”
Severodonetsk is a front-line city at growing risk of being encircled.
At least 12 people were killed and another 40 wounded by Russian shelling in the city, the regional governor said on Saturday.
Mr Zelensky said the bombardment was “brutal and absolutely pointless”, as residents cowering in basements described an unending ordeal of terror.
EVENING STANDARD