On July 25, 1979, President Marcus issued PD 1618 creating the autonomous regions (Sangguniang Pampook and Lupong
Tagapagpaganap ng Pook) of Regions IX and XII. There was without doubt general dissatisfaction within the OIC over the Philippine government’s implementation of the Tripoli Agreement. Perhaps this was one factor for Saudi Arabia’s decision to temporarily cut off its oil supply to the Philippines at the time; Iran’s complete stoppage of its oil shipment to the country.

Source: B.R. Rodil Kalinaw Mindanao; The Story of the GRP-MNLF Peace Process, 1975-1996