The Armed Forces of the Philippines (AFP) has to make clear its position with President Rodrigo Duterte even in closed doors regarding his decision to terminate the Visiting Forces Agreement with the United States, an international expert said on Thursday.

Renato de Castro, professor of International Studies in De La Salle University, said he could imagine the dilemma of the AFP now with the possible abrogation of the military treaty with Washington.

"Even in closed doorm you (military) have to make your position clear," he said when asked what he could advise to the military after Duterte ordered concerned officials to start the process of terminating the 21-year-old VFA.

He made the directive after the US canceled the visa of former Philippine National Police chief and now Senator Ronald dela Rosa.

Duterte has criticized the US Senate for passing a resolution, which was included in the US Budget Law banning Philippine government officials allegedly involved in human rights violations, including the continued detention of opposition Senator Leila de Lima.

De Castro noted that the VFA is necessary for the AFP's modernization, particularly the exercises with the US forces.

He also cited the role that US played during the Marawi siege and when super typhoon "Yolanda" struck most parts of the country in 2013.

While Malacanang said earlier that even if VFA is terminated, the Philippines has still the Mutual Defense Treaty and the Enhanced Cooperation Agreement, De Castro said the MDT and EDCA are "operationalized by the VFA because of the military exercise."

He also said Filipino soldiers who undergo training in the US are covered by the VFA.

"By removing (VFA), basically there goes the material component of the alliance and sooner or later what would be the use of MDT and EDCA if you will have no military exercises, no presence of foreign forces or American forces in the Philippine zone," he explained.

As to the possible effect of VFA abrogation with the US, the professor said, "is it showing loyalty or is it showing defection?"

The US is the first and longest strategic partner of the Philippines. Celerina Monte/DMS