The United States has provided intelligence that has helped Ukrainians target and kill many of the Russian generals who have died in action in the Ukraine war, according to senior U.S. officials.

Ukrainian officials said they have killed approximately 12 generals on the front lines, a number that has astonished military analysts.

The targeting help is part of a classified effort by the administration of U.S. President Joe Biden to provide real-time battlefield intelligence to Ukraine. That intelligence also includes anticipated Russian troop movements gleaned from recent U.S. assessments of Moscow’s secret battle plan for the fighting in the Donbas region of eastern Ukraine, the officials said. Officials declined to specify how many generals had been killed as a result of U.S. assistance.