world. A few days later, South Korean President Lee Myung-bak and Russian President Dmitry Medvedev agreed in a phone call that a strong international response was needed, including U.N. action, Lee's office said. Russia said that it will work with Seoul on a new U.N. Security Council resolution and to revive international talks on the North Korean nuclear issue. Human migration Koryo-saram is the name which ethnic Koreans in the Post-Soviet states use to refer to themselves. Approximately 500,000 ethnic Koreans reside in the former USSR, primarily in the newly independent states of Central Asia. There are also large Korean communities in southern Russia (around Volgograd), the Caucasus, and southern Ukraine. These communities can be traced back to the Koreans who were living in the Russian Far East during the late 19th century. There is also a separate ethnic Korean community on the island of Sakhalin, typically referred to as Sakhalin Koreans. Some may identify as Koryo-saram, but many do not. Unlike the communities on the Russian mainland, which consist mostly of immigrants from the late 19th and early 20th centuries, the ancestors of the Sakhalin Koreans came as immigrants from Gyeongsang and Jeolla provinces in the late 1930s and early 1940s, forced into service by the Japanese government to work in coal mines in order to fill labour shortages caused by World War II. Russians in Korea began arriving as early as 1885; however, virtually all of the current Russian community in South Korea, estimated at about 10,000 people, is composed of recent migrants. Cultural exchange There have been cases of cultural exchange between the two countries before the official diplomatic recognition. The introduction of Korean literature to the Russophone area was relatively active until the 1970s mainly through Korean classical stories. References Further reading Kim, Taewoo. "The Intensification of Russophobia in Korea from Late Chosŏn to the Colonial Period: Focusing on the Role of Japan." Seoul Journal of Korean Studies 31.1 (2018): 21-46. Kristensen, Hans M., and Robert S. Norris. "A history of US nuclear weapons in South Korea." Bulletin of the Atomic Scientists 73.6 (2017): 349-357. online Kukla, Marina. "Russia’s Turn to the East: Rethinking Economic Cooperation between Russia and South Korea." Problemy Dalnego Vostoka 2 (2020): 71-83. online Lee, Sun-Woo, and Hyungjin Cho. "A Subtle Difference between Russia and China’s Stances toward the Korean Peninsula and Its Strategic Implications for South Korea." Journal of International and