Chinese President Xi Jinping has instructed the country's army to increase military pressure in the southwestern region of Taiwan, sources familiar with the matter said Tuesday.

Xi's instruction came at a recent meeting of the Central Military Commission, China's highest military authority, after six democratic nations including the United States and Japan carried out joint military drills near Taiwan earlier this month involving three aircraft carriers.

A large number of Chinese military planes have entered Taiwan's air defense identification zone (ADIZ) since last Friday, in an apparent bid to counter the military exercises conducted by Britain, Canada, Japan, the Netherlands, New Zealand and the United States.