The number of Russian troops killed and wounded in Ukraine is approaching 200,000, a stark symbol of how badly Russian President Vladimir Putin’s invasion has gone, according to U.S. and other Western officials.

While the officials caution that casualties are notoriously difficult to estimate, particularly because Russia is believed to routinely undercount its war dead and injured, they say the slaughter from fighting in and around the eastern Ukrainian city of Bakhmut and the town of Soledar has ballooned what was already a heavy toll.

With Moscow desperate for a major battlefield victory and viewing Bakhmut as the key to seizing the entire eastern Donbas area, the Russian military has sent poorly trained recruits and former convicts to the front lines, straight into the path of Ukrainian shelling and machine guns. The result, U.S. officials say, has been hundreds of troops killed or injured a day.