A battle group was also sent to the central Pacific in August and September to pursue the German East Asiatic squadron, which then moved into the Southern Atlantic, where it encountered British naval forces and was destroyed at the Falkland Islands. Japan also seized German possessions in northern Micronesia, which remained Japanese colonies until the end of World War II, under the League of Nations' South Seas Mandate. Hard pressed in Europe, where she had only a narrow margin of superiority against Germany, Britain had requested, but was denied, the loan of Japan's four newly built "Kongō"-class battlecruisers (, , , and ), some of the first ships in the world to be equipped with guns, and the most formidable battlecruisers in the world at the time.