Ukrainian troops are strengthening fortifications in the Sumy region, in the northeast of the country, an official has said.
Vadym Mysnyk told the Ukrainian news agency Ukrinform that exercises were being carried out in the area "to protect the state border".
"The defence forces in the Sumy region perform combat tasks to protect the state border and prevent Russian sabotage and reconnaissance groups and the Russian military from crossing the border," he said.
Border communities such as Sumy have come under repeated Russian shelling and airstrikes since Russia's invasion.
https://news.sky.com/story/ukraine-war-russia-news-putin-nuclear-live-updates-kyiv-12541713
