China issued a map showing six zones around Taiwan that would be the site of air and sea exercises, and long-range live-fire drills in coming days – part of what a spokesman described as a "blockade." Ships and aircraft have been warned to stay out of the areas during the drills.

On Thursday, Taiwan's Maritime and Port Bureau said China had added a seventh military exercise area for ships and aircraft to avoid "in the waters around eastern Taiwan."

The exercise areas announced by Beijing extend well into Taiwan's air defense identification zone – a buffer of airspace commonly referred to as an ADIZ – and in some cases come within 12 nautical miles (22.2 kilometers) of its shores. Twelve nautical miles is the distance that international law defines as constituting a country's territorial airspace.

Analysts say it's an extremely provocative move.