State visit
国家元首访问
A state visit is a formal visit by one head of state to another country,at the invitation of the other country's head of state.State visits are the highest form of diplomatic contact between two states,and are marked by major ceremonial and diplomatic formality.In parliamentary democracies,though the heads of state may formally issue and accept the invitation to visit,they do so on the instruction of their governments,who usually agree together on when the invitation is to be issued in advance.