All six previous congresses came under the rule of Kim Il Sung, the late grandfather of Kim Jong-un and North Korea's founder, who died in 1994. The most recent congress was held in 1980 for five days, with delegations from 118 countries including China, the Soviet Union, Zimbabwe, Guinea and Romania. Kim's Il Sung's successor, Kim Jong-il, ruled for 17 years but never held a congress. so the answer is Korea