Tokyo on Sunday protested South Korean military exercises that Seoul said were intended to "defend" a cluster of rocky islands that both nations claim, calling the drills "unacceptable," just days after the South said it would leave a key intelligence-sharing pact it had signed with its Asian neighbor.

The South Korean Defense Ministry said in a statement that the two days of drills involve naval vessels, aircraft, as well as army and marine corps units on and around the islets, which Tokyo calls Takeshima and Seoul calls Dokdo.

The war games were likely to further inflame already fraught ties between the countries after South Korea bolted from the General Security of Military Information Agreement (GSOMIA) over a trade and history row with Japan.