This was in violation of an earlier commitment.

China’s deployment on its territory of “necessary defense facilities is a right that every sovereign country has and is in line international law which is beyond reproach,” Wang Wenbin, spokesperson for the Foreign Ministry, told reporters at a daily briefing.

Wang stated that U.S. military operations in the region were intended to “stir up tension and make provocations.” “That seriously compromises the sovereignty, security and order of coastal countries, and undermines navigation safety in South China Sea.”

U.S. Indo-Pacific Commander Adm. John C. Aquilino stated Sunday that China had equipped the islands using anti-ship and aircraft missile systems, laser jamming equipment and fighter jets in an aggressive move that threatens all countries operating near it.

Aquilino stated that the hostile actions were completely in contrast to Chinese President Xi Jinping’s previous assurances that Beijing would never transform artificial islands in contested waters in military bases. He said that China was trying to show its military might by putting forth these efforts.

“I believe that over the past twenty years we’ve seen the largest military buildup by the PRC,” Aquilino stated to The Associated Press using the initials of China’s formal name. They have advanced all of their capabilities, and that building up of weaponization is destabilizing for the region.”

China claims the entirety of the South China Sea as its territory. This area is home to fish stocks, undersea minerals and sea lanes that carry an estimated $5 trillion worth of global trade each year.

China refused to recognize claims by five other countries to the waterway. It also rejected the findings of an U.N.-backed arbitration panel that invalidated China’s broad historical claims under the U.N. Convention on the Law of the Sea.

These militarized islands were built by China in recent years on top of coral reefs. This has caused severe damage to the marine environment.