North Korea has fired a missile over northern Japan

China must play a greater role in curbing North Korea after its latest missile firing, says a leading Japanese diplomat.

Shinichi Iida, minister at the Japanese embassy in London, said the US president and Japanese prime minister agreed that they are going to convene at the emergency session of the UN secretary council.

He said China could play a great role since 90% of North Korea's external trade - in terms of value - comes from China.