China will speed up exports of rare earth minerals to Japan, the Japanese trade minister said Saturday, following complaints from Tokyo that shipments were stalled amid a territorial row.

Trade minister Akihiro Ohata said that Zhang Ping, chairman of China's National Development and Reform Commission, told him that he had "instructed (officials) to speed up inspections at customs to be more efficient".

Ohata was briefing reporters on the sidelines of the summit of Asia Pacific Economic Cooperation nations in Yokohama, south of Tokyo.

Zhang had told Ohata that China's "tightening of control over the rare earth industry is aimed at the orderly development and sustainable use of rare earth resources," the Japanese trade minister said.

"But he understands that Japan has interest in the freight stuck at customs, and that the NDRC has already contacted relevant organisations," said Ohata, adding that the issue of restricted shipments will be resolved soon.

China has a near-global monopoly in rare earths -- last year, it produced 97 percent of world supply. It has denied any embargo on shipments, including to Japan, amid a diplomatic row between the Asian neighbours.

The elements are used in everything from guided missiles to iPods and cars. Japan's high-tech industry is the world's largest consumer of rare earths.

Tokyo's row with Beijing stems from the arrest of a Chinese trawler captain whose vessel collided with Japanese patrol boats in waters near a disputed island chain in the East China Sea in September.

Prosecutors released the captain after Beijing cut political, economic and cultural exchanges, but the dispute continues to simmer and nationalists in both countries have staged protests.

Tokyo officials said that China had restricted rare earth shipments in the wake of the row, a claim Beijing repeatedly denied.

Since 2006, China has cut export quotas on rare earths by five to 10 percent a year. Production has also been slashed amid concerns that Chinese supplies could run out in 15 years.

China's moves to restrict exports have spurred other countries such as the United States and Australia -- which have 15 and five percent of reserves respectively -- to resume production.

On Friday China said it had toughened rare earth export rules to allow only producers that meet environmental protection laws and international standards to ship the precious elements out of the country.