White House spokesman John Kirby said the group had suffered significant losses in recent weeks, with about 9,000 fighters killed in action. Some of the fiercest fighting of the war has taken place around the eastern city, with Wagner mercenaries heavily involved in Russian efforts to capture it. Mr Prigozhin has blamed Moscow's "monstrous bureaucracy" for slowing down progress in Ukraine, and accused the Russian army of unfairly taking credit for previous Wagner successes