The “Immediate Combat Readiness Exercise” will run through Friday and forms part of Taiwan’s broader military modernization efforts to shift training toward realistic wartime scenarios and away from traditional scripted drills, the Ministry of National Defense said on Sunday.

The exercise comes as Taiwan increasingly bases portions of its military planning on the possibility that China could transform one of its frequent military operations around the island into a real attack with little warning.

According to the ministry, the drills will focus on improving the armed forces’ ability to conduct rapid transitions from peacetime to wartime conditions, while enhancing battlefield deployment, command coordination, logistical support and joint operational capabilities.

“The main objective is to train units at all levels to become familiar with combat practices and the battlefield environment during the readiness deployment phase,” the ministry said in a statement.

Officials said the exercise would involve troops operating in real-time conditions using actual equipment and terrain, reflecting Taiwan’s growing emphasis on combat-oriented training.

The announcement coincided with a new report of Chinese military activity near the island. Taiwan said 21 Chinese military aircraft, including J-16 fighter jets, KJ-500 airborne early warning aircraft and Y-20 aerial refueling planes, were detected operating near Taiwan on Sunday.

Nineteen of the aircraft entered airspace to Taiwan’s southwest and proceeded into the Western Pacific for what Taipei described as long-distance training missions over open seas.

Taiwan’s military said it monitored the activity and deployed forces to respond, using what it described as appropriate measures.

China, which views Taiwan as part of its territory despite the objections of the government in Taipei, has increased military operations around the island in recent years, regularly sending warships and aircraft into nearby waters and airspace.

Taiwan has responded by accelerating defense reforms, expanding reserve-force training and increasing the realism of military exercises designed to prepare for a potential cross-strait conflict.

Earlier this month, Taiwan conducted live-fire tests of its newly acquired U.S.-made High Mobility Artillery Rocket System (HIMARS), a weapon platform that has gained prominence through its battlefield use in UkraineTaiwan’s annual Han Kuang military exercises, the island’s largest war games, are expected to take place in August.