 At this stage , Hitler ordered the final destruction of Leningrad with no prisoners taken , and on 9 September , Army Group North began the final push . Within ten days it had advanced within 11 kilometers of the city . However , the push over the last 10 km ( 6 @.@ 2 mi ) proved very slow and casualties mounted . Hitler , now out of patience , ordered that Leningrad should not be stormed , but rather starved into submission . Deprived of its Panzer forces , Army Group Center remained static and was subjected to numerous Soviet counterattacks , in particular the Yelnya Offensive , in which the Germans suffered their first major tactical defeat since their invasion began . These attacks prompted Hitler to concentrate his attention back to Army Group Center and its drive on Moscow . The Germans ordered the 3rd and 4th Panzer Armies to break off their Siege of Leningrad and support Army Group Center in its attack on Moscow . 
