KYIV, Sept. 12 -- More than half a million Russian troops have been killed in Ukraine since the start of Moscow's full-scale invasion in February 2022, a senior British defense official said Friday. The dead are part of 1.5 million Russian casualties in Ukraine, Air Chief Marshall Sir Richard Knighton, Chief of the U.K's Defense Staff, said. The U.K. figures roughly coincide with those published by the Ukrainian military. There was no immediate comment from Russian officials. Moscow's bigger army is struggling to make headway on the battlefield. Western officials and analysts say the Russian rate of advance has slowed significantly this year. Russia's armed forces have also lost an "enormous" amount of military materiel, Knighton told reporters. That includes more than 10,000 armored and protected vehicles, close to 3,000 air defense and artillery systems, and over 370 aircraft and helicopters, Knighton said.AP...