MANILA (PHILIPPINE DAILY INQUIRER/ASIA NEWS NETWORK) - Philippine President Rodrigo Duterte has reappointed five special envoys to China to improve ties with Beijing strained by a long-standing maritime dispute over conflicting claims to parts of the South China Sea.

Duterte signed the reappointment papers of Ferdinand Borja, Wallie Lee, Carlos Chan, Cheng Yong, William de Jesus Lima as special envoys to China on Jan 3.

"They are his envoys to promote closer relationship with China," Presidential Spokesperson Harry Roque said in a text message when asked if why was there a need to have five special envoys to China.

Borja, Lee, Chan, and Lima had previously served as Duterte's special envoys to China in the previous months. Their new term starts from January 1 to June 30, 2018.

Yong will also serve for six months but his term of office was not indicated in his appointment paper.

In July 2016, former president Fidel Ramos accepted the post as special envoy to China in the wake of the Philippines' historic victory in the United Nations-backed arbitral tribunal in The Hague, which invalidated China's claims to almost all of the resource-rich South China Sea.

Ramos, however, resigned on October 2016, citing he has already "done my job … to break the ice and to help restore the ties of goodwill and friendship."

Duterte also reappointed Century Properties Group Chairman and CEO Jose E.B. Antonio as his special envoy to the United States.

Miguel Ayala was also appointed as his special envoy to Australia from Jan 1 to June 30, 2018.