Ruling parties want clean energy to make up "significantly" more than 20 percent of the nation's power by 2030.

The Liberal Democratic Party and New Komeito, its coalition party, have been reviewing a draft of the country's long-term energy policy plan presented by the government in February.

The parties agreed that they want the target to be included in the final plan, said Taku Yamamoto of the LDP at a briefing Friday. Their goal uses a stronger expression than the "more than 20 percent" target suggested by officials of the Ministry of Economy, Trade and Industry, Yamamoto said.