China has deployed nearly 100 naval and coast guard vessels in and around the South and East China Seas, according to Taiwanese security officials. The increase is seen as rare as this time of year is usually busy for Chinese naval drills. The timing of the increased presence coincides with Washington's focus on Iran and Taiwan's opposition leader, Cheng, visiting China. The number of vessels was corroborated by intelligence reports reviewed by Reuters. Tsai Ming-yen, head of Taiwan's National Security Bureau, believes China may be using this activity to test how often U.S. aircraft operate in the area.