The Norwegian Sea is ice-free and provides a direct route from the Atlantic to the Russian ports in the Arctic (Murmansk, Arkhangelsk, and Kandalaksha), which are directly linked to central Russia. This route was extensively used for supplies during World War II – of 811 US ships, 720 reached Russian ports, bringing some 4 million tonnes of cargo that included about 5,000 tanks and 7,000 aircraft. The Allies lost 18 convoys and 89 merchant ships on this route. The major operations of the German Navy against the convoys included PQ 17 in July 1942, the Battle of the Barents Sea in December 1942, and the Battle of the North Cape in December 1943 and were carried out around the border between the Norwegian Sea and Barents Sea, near the North Cape.