The plan aims to have 22-24 percent of Japan's energy needs met by renewable sources including wind and solar by 2030, a figure critics describe as unambitious based on current levels of around 15 percent.

Japan's own Foreign Minister Taro Kono earlier this year called the goal "significantly low" and described the country's commitment to renewables as "lamentable".

The European Union this month agreed to raise its renewable energy target to 32 percent by 2030.

Japan's policy also envisions nuclear providing more than 20 percent of the country's energy needs by 2030, reflecting the government's ongoing commitment to the sector despite deep public concern after the 2011 Fukushima disaster.

The government has reduced Japan's reliance on the sector, but defends nuclear as an emissions-free energy source that will help the country meet its climate change commitments.

Critics though say the government has done too little to push renewable energy as a viable option.

Japan currently generates around 90 percent of its energy from fossil fuels, and the plan calls for that figure to drop to just over half, with energy efficiency policies to cut demand.

Reliance on fossil fuels like coal increased in Japan after the Fukushima disaster, as public anger over the accident pushed all of the country's nuclear reactors offline temporarily.

Six reactors are currently operating, and utilities face public opposition to activating more despite political support for the nuclear industry.

Japan's TEPCO, which operated the Fukushima plant, signalled last week that it was ready to resume work on the construction of a new nuclear plant in the country's north.

"While we have strong obligations resulting from the Fukushima accident, we believe that it is our duty to ensure sufficient electricity supplies to avoid cuts," TEPCO chief Tomoaki Kobayakawa said Friday.

The government's plan also includes a pledge to reduce the country's 47-tonne stockpile of plutonium, which is large enough to produce 6,000 atomic bombs, though it is mostly stored overseas.

Japan has sought to generate energy from the material, but decades of research has not produced an effective and commercially viable method, leading to international criticism of Tokyo for continuing to produce and possess plutonium.

hih/sah/mtp

TEPCO - TOKYO ELECTRIC POWER