China says the deployment of military equipment on islands in the South China Sea is legitimate. The remarks by the foreign ministry come after a US think tank reported that China installed weapons on seven islands in the region.

"I want to reiterate, the islands in the South China Sea are China's inherent territory. China's building of facilities and necessary territorial defensive facilities on its own territory is completely normal. This is the normal right of a sovereign nation under international law," said Geng Shuang, spokesperson of Chinese Foreign Ministry.

Chinese planes recently passed through the Miyako Strait between Japan's Miyako and Okinawa Islands. The Chinese Air Force said the flights were "routine" and that regular maritime drills will continue to "further improve its capabilities in safeguarding national sovereignty, security and development interests". The strait is a pinch point in China-Japan relations because it is one of the few passages into the Pacific Ocean for Chinese ships and aircraft that avoid Japanese airspace.