Japan has recorded its biggest monthly trade deficit with China, as the US seems poised to supplant China as the country’s top export destination.

Government data showed that Japan’s exports to China fell 12 per cent in October from a year earlier to Y948bn ($12bn), as shipments of cars and machinery were knocked by a territorial dispute between Asia’s two largest economies. Japan’s imports from China were up 4 per cent from a year earlier to Y1.35tn, buoyed by demand for Apple’s iPhone 5, which is assembled in China.

Excluding the distorting effects of lunar new year holidays, which have driven the monthly bilateral trade balance deeper into negative territory three times since 2006, last month’s deficit of Y406bn was easily the widest in records going back to 1979.