Ukrainian prosecutors have launched an investigation into an alleged Russian execution of a Ukrainian soldier found dead with a sword inscribed with “for Kursk” in his body, in an apparent act of revenge for Kyiv’s recent incursion into the Russian border region.

With its bold strike into Kursk, Ukraine’s leadership primarily aims to bolster the morale of the nation and the allied coalition; a gamble which if successful could upend the trajectory of the war.

Russia said on Friday that its army would regain control of its Kursk region "in a timely manner", declining to say how soon this could be achieved.