It is a souvenir cup awarded by 中央慰问团 The Consolation Troup of the Chinese Central Government. Consolation groups were established in different areas to support the maintaining of peace and resist US imperialism in Korea.
It reads, 为全世界人民服务 “Service to all people of the world.” View a large Mao badge with the phrase “Service to the people.” Note the deep tea stains in the cup.
Back view. Image of Tian An Men.