President Rodrigo Duterte and United States President Donald Trump may maximize the opportunity to discuss issues concerning both countries during their first face-to-face meeting at the Asia Pacific Economic Cooperation Summit in Vietnam later this week, an official said on Monday.

In a press briefing in Malacanang, Department of Foreign Affairs Assistant Secretary Leo Herrera-Lim said it was not sure yet if Duterte and Trump would have a bilateral meeting at the APEC sidelines.

"Once you’re there in Da Nang, the opportunity (to talk with each other) increases. So I think most likely they will --- meaning, they, the US will seek out our President to even have a --- at best a meeting on the sidelines of APEC," he said.

"And I think that fact that it’s a first face-to-face meeting, sometimes both parties will try to maximize the opportunity," he said.

Duterte is set to leave for Vietnam on Wednesday and will return on Saturday in time for the Philippine hosting of the ASEAN and East Asia Summits on November 12-14.

Lim said Duterte might also have bilateral meetings with his counterparts from China, Vietnam and Russia in Da Nang.

Lim added that among the presidents elected in 2016, "it’s our president that continues to get attraction in the international fora."

If there will be a chance for Duterte and Trump to have exchanges at the APEC sidelines, some of the issues that could discussed are on national security, both at the country level and at the regional level; and the desire to grow the different engines of global economy, he said.

Duterte and Trump spoke to each other twice via telephone since the Philippine leader assumed post in June last year.

Trump is set to attend also the 31st Association of Southeast Asian Nations Summit and Related Summits in Manila.

Both governments are working to have a formal bilateral meeting of the two leaders at the sidelines of ASEAN meetings. Celerina Monte/DMS