The aircraft was carrying troops bound for counterinsurgency operations when it crashed with 96 aboard, killing 53 in the country's worst military air accident in nearly three decades. Among the dead were three civilians on the ground and the rest of the crew were injured.
Asked if bad weather or human error could be the reason for the incident, Sobejana said he would await the investigators' official report.
“I told them to do it as fast as we can, but this should be deliberate,” he said. “We wanted to get the accurate information or the facts.”
US Defence Secretary Lloyd Austin offered additional support to Philippines counterpart Delfin Lorenzana when they spoke by phone on Tuesday to discuss the crash.
They also discussed critical medical evacuation support provided by US personnel and other possible assistance, including victim identification, according to a statement released in Washington.
Sobejana said 16 of the casualties have been identified.
Some victims were burnt beyond recognition, and authorities would rely on the dental records and forensic testing to identify them, he said.