Japan's exports to South Korea sharply declined last month amid escalating tensions between the two nations.Tokyo's finance ministry says Japan's shipments to Korea in October were down some 23 percent on-year to around 3-point-5 billion U.S. dollars.In particular, food, automobiles and semiconductors saw large declines.Exports have fallen due mainly to a South Korean boycott of Japanese goods stemming from Tokyo's trade restrictions and historical disputes.Japan saw its trade surplus with Korea tumble by more than 41 percent on-year last month.