China has restarted construction of its first new nuclear reactor since Japan's Fukushima disaster in 2011, state media said Wednesday.

Work on the fourth reactor at the Hongyanhe nuclear power station in the north-eastern province of Liaoning had completed the first stage, but was frozen along with all other nuclear projects in 2011.

Permission for the second phase of construction had now been granted by China's top economic planning organization, Xinhua news agency said, citing an unnamed company source speaking Tuesday.

China suspended new plant approvals and all construction to conduct a safety review after Japan's Fukushima Daiichi Nuclear Power Station suffered a triple meltdown when it was hit by an earthquake and tsunami in March 2011.

Last year Beijing said it would restart nuclear power generation in its highly populated eastern coastal areas, where demand is strongest, adhering to the highest international safety standards.

The country currently has 23 nuclear power reactors in operation, with 26 under construction, according to a report from the World Nuclear Association which was updated last month.

China has pledged to reduce its reliance on coal, currently the source of most of its electricity.

A government plan issued last year aims to ensure coal burning reaches no higher than 4.2 billion tonnes per year by 2020 and for the share of non-fossil fuels in the energy mix to rise to 15 per cent by the same year.