As a result, last year Japan was no longer the world's biggest LNG importer and was overtaken by China.

After shutting down its 54 nuclear reactors following the 2011 Fukushima nuclear disaster, Japan started to gradually restart nuclear power plants in 2015.

Eleven nuclear reactors with a total capacity of 10.7 gigawatts are in operation, of 12 that have been cleared to generate electricity.

Together with increased solar and wind generation, the nuclear power allowed a further reduction in LNG imports, which reached a peak of 88.5 million tones in 2014.

According to the Ministry of Finance's preliminary data, Japan spent 6.5 trillion yen ($44 billion) on LNG purchases last year, a drop of almost 23% from a year ago, with LNG accounting for 6% of total country imports in value terms.

Although the preliminary data did not provide the full country breakdown, it showed LNG imports from the United States rose by 34% to 5.5 million tons from a year ago. Purchases from the Middle East and Russia were down by 12% and 11% to 6 million tons and 6.1 million tons, respectively.

Separately, LNG inventories held by Japanese electric utilities, an indicator of the size of stockpiles, were down to 2.49 million tons as of Jan. 21, data released by the Ministry of Economy, Trade and Industry (METI) showed.

Although below the year-end level of 2.70 million tons, stockpiles were above 2.39 million tons held as of end-January last year and higher than the 1.91 million-ton 5-year average for the month, according to METI.

In its statement, METI did not explain the LNG stockpile figures.

Japan was hit by a powerful earthquake on New Year's Day causing water spillover from spent nuclear fuel pools and oil leaks at an idled nuclear power station in the Hokuriku region, reviving concern about the industry's safety.

($1 = 147.7000 yen)