Taiwanese President Ma Ying-jeou says that the highest-ranking Chinese envoy ever to visit Taiwan has had a successful trip. But Ma said Thursday challenges still exist between the rivals that split amid civil war in 1949. Ma says the two sides still have to resolve disputes about security and Taiwan's international status. The highly anticipated meeting between Ma and Chinese envoy Chen Yunlin was held as hundreds of protesters gathered in the streets outside. They oppose closer ties with China.