TOKYO, July 17 (Xinhua) -- A bilateral nuclear pact made between Japan and the United States authorizing Japan to reprocess spent fuel from nuclear reactors, extract plutonium and enrich uranium, was extended Tuesday amid international concern about Japan's plutonium stockpiles.

Along with the United States, a number of other countries have expressed concern about Japan's plutonium stockpiles, but as neither side reviewed the pact after the 30-year term beginning in July 1988, it has been extended by default.

The extension of the pact, which can be terminated by either side six months after notification is given, has raised concerns over the future course of action regarding Japan's extensive stockpiles.

Japan currently has 47 tons of plutonium and while it is the only country without nuclear weapons that is allowed to reprocess spent nuclear fuel, it has enough plutonium to theoretically make about 6,000 plutonium-cored atomic bombs.

Japan's Foreign Minister Taro Kono on Tuesday told a press briefing on the matter that Japan intends to reduce the amount of plutonium it possesses.

"Japan will do all it can to maintain the nuclear nonproliferation regime while keeping the Japan-U.S. nuclear pact," Kono said.

"It will be important to make efforts toward reducing the large amount of plutonium that Japan possesses," he added, referring to an energy plan outlined in July.

Under pressure from the international community, the Japan Atomic Energy Commission (JAEC), which operates under the auspices of the Cabinet Office, outlined in July its plan to reduce the stockpile of plutonium.

In the commission's latest white paper on nuclear power utilization, it states that its goal is to reduce the plutonium stockpile by a nuclear power generation method utilizing fuel recycling.

This method, stated in the white paper and referred to as the only realistic way to reduce the stockpile, is known as plutonium-thermal (pluthermal) power generation.

Pluthermal power generation sees plutonium- uranium mixed oxide (MOX) fuel burned at fast-breeder or normal nuclear reactors.

However, following the 2011 Fukushima nuclear disaster, the majority of Japan's nuclear reactors remain offline for safety inspections amid widespread public opposition over the safety of the aged plants.

The administration of Prime Minister Shinzo Abe, nevertheless, is pushing for the restart of the idled reactors following their clearance of enhanced safety inspections in the wake of the Fukushima disaster.

But amid public concern over safety, the JAEC's time-frame for lowering Japan's plutonium stockpiles by pluthermal power generation, remains uncertain.