China has pressed Japan not to broach Beijing's disputes with regional neighbors in the South China Sea at the upcoming Group of Seven summit to be held in Japan in May, arguing that touching on the issue would hamper efforts to improve bilateral relations, diplomatic sources said Saturday.

China pressed the point to Japan at a vice foreign ministerial gathering held in Tokyo in late February, according to the sources.

But Japan rebuffed the Chinese demand, saying the international community cannot accept China's building of artificial islands in the sea and their militarization, they said.