SINGAPORE — China’s land reclamation in the South China Sea is out of step with international rules, and turning underwater land into airfields won’t expand its sovereignty, Defense Secretary Ash Carter told an international security conference Saturday, stepping up America’s condemnation of the communist giant as Beijing officials sat in the audience.

Carter told the room full of Asia-Pacific leaders and experts that the U.S. opposes “any further militarization” of the disputed lands.

His remarks were immediately slammed as “groundless and not constructive” by a Chinese military officer in the audience.

Carter’s comments came as defense officials revealed that China had put two large artillery vehicles on one of the artificial islands it is creating in the South China Sea. The discovery, made at least several weeks ago, fuels fears in the U.S and across the Asia-Pacific that China will try to use the land reclamation projects for military purposes.

The weaponry was discovered at least several weeks ago, and two U.S. officials who are familiar with intelligence about the vehicles say they have been removed. The officials weren’t authorized to discuss the intelligence and spoke only on condition of anonymity.

The Pentagon would not release any photos to support its contention that the vehicles were there.

Read more: http://www.nytimes.com/aponline/2015/05/29/world/asia/ap-as-united-states-china.html?_r=0