Ukrainian forces are bracing for another major frontline assault from Russia after learning of a large build-up of pre-battle troops in the north east.

Statements by Russian President Vladimir Putin about creating a buffer zone are evidence of the Russian Federation's aggression, said Heorhii Tykhyi, spokesperson for Ukraine's Ministry of Foreign Affairs.

Ukrainian forces made a surprise incursion into Kursk in August 2024, before being pushed out by Russian troops nine months later.