A government official from Hainan province (4th right) speaks at a symposium on Hainan-Hong Kong cooperation in modern service industry development in the South China island province Tuesday. A signing ceremony for investment and cooperation agreements between the two governments was also held Tuesday. Hong Kong is now the leading source of overseas private investment in Hainan, where the drive to build the subtropical island into a top international tourist destination has been elevated to a constituent of "the national development strategy" since last year.