The Philippines and Japan signed the Reciprocal Access Agreement (RAA) on Monday in Manila's Malacañang Palace.
RAA fosters greater defense cooperation by allowing Japanese Forces to train with the Philippine military and ease access between the two countries for troops.
The pact upgrades bilateral relations between Manila and Tokyo, and is "seen to provide a broader alliance against China, which in recent months has been increasingly assertive in its ambitious claims in the West Philippine Sea," said the Philippine Government.
This development comes as China continues to ramp up tensions in the South China Sea.
According to Nikkei Asia, Philippine Armed Forces chief of staff Gen. Romeo Brawner said the RAA will allow the Philippines to conduct more than just humanitarian assistance and disaster relief operations, but "actual military operations."
The Philippines government said the treaty will have to be ratified by the respective legislative bodies of both countries before it goes into force.
Once it does, the RAA with Manila will be Japan's third defense cooperation agreement with other countries, including the United Kingdom.