Methods for a foreigner to acquire nationality of the Republic of Korea include general naturalization, simplified naturalization, and special naturalization. People who once held nationality of the Republic of Korea but now only hold foreign nationality can reacquire such through restoration of the nationality of the Republic of Korea. Individuals with multiple nationalities must select one within a certain period, but they may also pledge not to exercise their foreign nationality and maintain their multiple nationality. In addition, people from North Korea or Sakhalin whose nationality status in the Republic of Korea is unclear can apply for a nationality determination.