Philippine President Rodrigo Duterte, in an apparent policy shift, said on Wednesday he planned to ask China to make clear its intentions in the disputed South China Sea during Asia-Pacific Economic Cooperation (APEC) meetings in Vietnam.

China claims almost the entire strategic waterway where $3 trillion worth of sea-borne goods passes every year, building and militarizing artificial islands. Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have conflicting claims.

"So, it's about time, either in the bilateral or in the plenary, I should be bringing this important matter to the surface," Duterte told reporters before leaving for Vietnam.