TOKYO » Japan’s trade minister urged China on Sunday to resume exports to Japan of crucial manufacturing materials that Japanese officials consider effectively banned since last month amid a territorial row between the two Asian powers.

Japanese companies say Beijing has blocked shipments of rare earth metals to Japan since Sept. 21 in possible retaliation for Tokyo’s arrest of a Chinese fishing boat captain near disputed islands in the East China Sea.

The captain, whose fishing trawler collided with two Japanese patrol boats, was later released. Beijing denies any official ban on shipments to Japan, but Japanese companies and officials say supplies have yet to resume.

Trade Minister Akihiro Ohata told visiting Chinese Vice Minister of Commerce Jiang Yaoping that disrupted shipments of the exotic minerals, used in computer disk drives, hybrid car components and other high-tech products, could hurt the two Asian economies.

Jiang, in Tokyo to attend a Japan-China energy conservation forum, reiterated that there is no "intentional" trade embargo. He blamed "a rise in illegal shipments" for forcing authorities to step up customs inspections, Ohata said.

Jiang also said that China has increased inspections of rare earths shipments to other countries, not just Japan, according to Japanese media reports.

Jiang "said he would make efforts so that the situation would not cause any adverse effects on the economies of Japan and China," Ohata told reporters.

The territorial dispute has prompted concerns in Japan about regional security.

Prime Minister Naoto Kan told a ceremony marking armed forces day Sunday that Japan faces "severe" regional security threats because of North Korea’s missile and nuclear development and China’s growing military presence and marine activity.

"We need to maintain readiness of our defense forces so that we can effectively deal with any situation," Kan said in a speech at an army base near Tokyo.

As anti-Japan rallies continued in Chinese cities over the weekend with hundreds of protesters demanding Japan drop its claim to islands called Senkaku in Japan and Diaoyu in China, Ohata asked Jiang to ensure the safety of Japanese citizens and companies in China. Jiang’s response was not immediately known, but Beijing has promised to protect their safety.

The disruption in rare earth shipments has shaken Japanese industry, which is now looking for other suppliers of the exotic metals and is considering becoming a rare earth recycling center.

The Chinese Commerce Ministry said last week it will limit exports of rare earths to protect its environment. Its plan has prompted mining companies in the United States and Canada to launch efforts to resume production.