The changes were instructed by President Rodrigo Duterte who has said he wants to chart a foreign policy less oriented toward Washington while expanding security ties with China and Russia.
He has taken a softer stance than his predecessor on the territorial disputes with China in the South China Sea.
Opening rites for the "Balikatan" or "Shoulder-to- Shoulder" exercises were led Monday by Defense Secretary Delfin Lorenzana and US Ambassador Sung Kim at the Philippine military's headquarters in metropolitan Manila.