China’s military warned it would ramp up pressure on Taiwan when necessary, a sign that the US-backed democracy of 23 million people can expect a repeat of the intense exercises seen to start the week.

Taiwan is particularly wary of Chinese coast guard efforts to board its civilian ships on law enforcement grounds. Such instances could be a very serious provocation that Taiwan's coast guard would do everything to prevent, its deputy chief, Hsieh Ching-chin, said on Monday.

China staged a major military exercise around Taiwan on Monday, issuing a "serious warning" to the "separatist" forces of the island amid soaring tensions in the region. Ships and aircraft approached from several directions.