Ukrainian President Volodymyr Zelenskiy has accused Russian soldiers of deliberately mining areas in northern Ukraine as they withdraw or are pushed out by Ukrainian forces.

Ukraine says its troops have retaken control of more than 30 towns and villages in the Kyiv region since Russia announced this week it would scale down its operations around the capital and in the neighbouring northern region of Chernihiv to focus on battles in the east.

"In the north of our country, the invaders are...