The T34/85 was the core of the North Korean and Chinese armoured units during the Korean War. A Second World War design, the T34/85 had originally been developed by the Soviets for fighting on the Eastern Front and had excellent cross-country mobility. The tank's 85 mm gun packed a considerable punch and in the early days of the war North Korea's T-34/85s completely overwhelmed the American light M24 Chaffee tanks employed against them. They were soon matched, however, by increasing numbers of heavy tanks hurriedly shipped in from America, such as the M26 Pershing.