Erlinda Basilio, 68, who as a foreign department undersecretary helped draft national diplomatic policy, will take over a post that was effectively vacant as the two neighbours' quarrel over the Scarborough Shoal simmered.

"This sends a signal of how important our relations with China are and how serious we are in trying to achieve an understanding with them," Aquino said of Basilio's appointment.

Diplomatic sources said Basilio had helped draft the Philippines' hardline stance against China's controversial claims, which have irked Beijing.

The foreign department said in a statement that Basilio was well-versed on the issues, adding: "we are relying on her to enhance the bilateral relations between the Philippines and our very important neighbour and friend, China".

Basilio previously served as ambassador to Sweden and representative to the Philippine mission to the United Nations Office at Geneva.