The delays in shipments to China have been caused by increased vetting by customs officials in Guangzhou, Shanghai and Tianjin, an official with the Japan External Trade Organization, Yumiko Yoshimura, said Monday. However, the situation was normal in other major cities such as Beijing, Dalian and Qingdao.
Kintetsu World Express, Japan's second-biggest freight-forwarding company, has cautioned its customers about possible delays at Chinese customs, although it hasn't received reports of any specific troubles. Sojitz Corp., a major trading firm specializing in China, said it was closely monitoring the situation but so far noticed no major delays or problems.
Total trade between China and Japan totalled $352 billion last year.
Tensions between China and Japan have spiked since the Japanese government earlier this month bought several disputed islands in the East China Sea from their Japanese owners. The move was aimed at blocking a more provocative plan by Tokyo's nationalistic governor to buy and develop the islands, which are surrounded by rich fishing grounds and untapped natural resources.
Still, Beijing responded to the purchase by promising "serious consequences," and Chinese rioters last week damaged Japanese-owned stores and factories in China.
In 2010, in a previous flare-up over the islands, Japanese imports to China faced increased customs delays. Beijing responded to Japan's arrest of a Chinese fisherman by imposing a de facto ban on exports of rare earths — special materials needed for advanced electronics equipment.
Japan on Monday dispatched a vice foreign minister to meet with his Chinese counterpart for talks on relations between the countries.
Meanwhile, China said it plans to use unmanned drones to conduct marine surveillance by 2015 as it tries to increase its presence around the uninhabited islands called Senkaku in Japan and Diaoyu in China. Li Mousheng, a spokesman for China's State Oceanic Administration, said the decision to deploy drones followed a successful test Sunday.
He offered no details on the test, but cited state media reports that said China aims to have drones and monitoring bases in place by 2015. The reports didn't say when the drones would be deployed around the islands.
Associated Press Writer Mari Yamaguchi in Tokyo and Christopher Bodeen in Beijing contributed to this report.