The trade ministry said Monday it has begun preparations for a second production test to extract methane gas from methane hydrate deposits off Japan's central coast.

The test is the first since Japan achieved the world's first extraction of gas in 2013 from offshore deposits of methane hydrate, a frozen gas known as "flammable ice."

Japan, which imports nearly all of its energy sources, has been aiming to launch private sector commercial production of methane hydrates by between 2023 to 2027, but the goal will still be a challenge as many obstacles remain to be solved, officials at the Ministry of Economy, Trade and Industry (METI) said.