Japan has unveiled its first draft energy policy since the Fukushima meltdowns three years ago, saying nuclear power remains an important source of electricity for the country.

The draft, presented to the cabinet on Tuesday for approval expected in March, says Japan's nuclear energy dependency will be reduced but that reactors meeting new safety standards set after the 2011 nuclear crisis should be restarted.

Japan has 48 commercial reactors, but all are offline until they pass the new safety requirements.

The draft of the Basic Energy Plan says a mix of nuclear, renewables and fossil fuel will be the most reliable and stable source of electricity to meet Japan's energy needs.

The government had planned to release the draft in January but a recommendation submitted by a panel of experts was judged to be too pro-nuclear. Tuesday's draft added more emphasis on renewable energy.

The economy, trade and industry minister, Toshimitsu Motegi, told reporters that "in principle, the direction has not changed". He called for additional efforts to accelerate the development of renewable energy over the next few years.

The draft says Japan will continue its nuclear fuel recycling policy, but adds there is a need for flexibility for possible later changes to the policy.

Japan has tonnes of spent fuel and a stockpile of extracted plutonium, causing international concerns about nuclear proliferation. Officials have said the most realistic way to consume and reduce the plutonium is to restart the reactors to burn it.

The previous energy plan in 2010 called for a boost in nuclear power to about half of Japan's electricity needs by 2030 from about one-third before the Fukushima disaster.