North Korea has removed all references to reunification with South Korea from its constitution, according to a document circulating on Wednesday. The revision marks a sharp break from decades of policy dating back to 1948, when Pyongyang had formally committed to pursuing unification. How has North Korea changed its constitution? The change was reported after the South Korean Unification Ministry shared a document seen by the country's Yonhap News Agency and international media. The updated constitution, introduced in March, also has a new clause defining North Korea's territory. It says this includes the area bordering China and Russia to the north, "and the Republic of Korea to the south," using South Korea 's official name. The revision also sees leader Kim Jong Un , as chairman of the State Affairs Commission, designated as North Korea's head of state. Previous ​language has described the chairman post differently — as the country's supreme leader who represents the state.…