China initiated large-scale military exercises in the vicinity of Taiwan on Monday, which it described as a “stern warning” to separatist and “external interference” factions, following the Trump Administration’s announcement of an arms sale to the island earlier this month.

China’s Eastern Theater Command announced that the “Justice Mission 2025” exercises—the first major drills conducted around the island since April—will encompass combat-readiness and port-blockade operations, featuring live fire and simulated land and sea attacks across seven zones surrounding the island, partially aimed at preventing external involvement.

Taiwan has governed itself since 1949, when Nationalist forces retreated to the island after being defeated by Chinese Communist forces. However, China has consistently claimed sovereignty over Taiwan and has long advocated for “reunification” between the island and the People’s Republic of China.

Senior Colonel Shi Yi, spokesperson for the Eastern Theater Command, stated that the exercises represent a “stern warning to Taiwan independence separatist forces and external interference forces,” and characterized the military action as a “necessary” step to safeguard China’s “sovereignty and national unity.”

Meanwhile, Taiwan’s Defense Ministry asserted that the exercises “further confirm” the Chinese Communist Party’s “character as an aggressor and the greatest threat to peace.”

According to Hsieh Jih-sheng, deputy chief of the general staff for intelligence at Taiwan’s Defense Ministry, China is deploying dozens of aircraft and drones in the Taiwan Strait during the exercises. The island’s Transport Ministry reported that over 100,000 passengers on international flights were expected to be impacted by the Chinese military’s activities.

Taiwan’s Civil Aviation Administration stated that the military exercises are anticipated to last until Tuesday.

The exercises occur amid China’s expressed anger over the $11.1 billion U.S. arms sale to Taiwan, which includes high mobility artillery rocket systems (HIMARS) and harpoon missile repair equipment. The U.S. had previously approved over $1 billion in arms sales to Taiwan in November.

In response to the sales, the Chinese foreign ministry imposed sanctions last week on 20 U.S. defense companies, preventing firms such as Boeing from conducting business with China. The sanctions also prohibited ten executives from those companies from entering China or engaging in commercial activities within the country.

The State Department informed Congress that it had approved the large-scale sale to Taiwan less than two weeks ago, stating that the potential agreement “serves U.S. national, economic, and security interests by supporting the recipient’s ongoing efforts to modernize its armed forces and maintain a credible defensive capability.”

The department’s statement added, “The proposed sale will help enhance the security of the recipient and support the maintenance of political stability, military balance, and economic progress in the region.”

Taiwan’s presidential office stated at the time that it was “sincerely grateful” for the announced sale, while China swiftly condemned it, claiming that it undermined Chinese sovereignty and security and destabilized peace and stability across the Taiwan Strait.