Japan is facing its most severe security environment since World War II as three potential adversaries in East Asia – China, Russia and North Korea – ramp up military activities in the region, the country’s defense minister said Tuesday.

The report highlighted a sharp rise in Chinese warship activity in the Pacific, especially near Japan's southwestern region. It noted that over the past three years, the number of Chinese naval transits near Taiwan and the Japanese island of Yonaguni has tripled.