Japan, host of the Group of Seven ministerial meeting on climate issues next month, has shown reluctance about bringing forward the framework's agreement last year to decarbonize power sector by 2035, sources close to the matter said Wednesday.

The G-7 gathering on climate, energy and environment issues on April 15-16 in Sapporo, northern Japan, is set to focus on the seven developed countries' decarbonization efforts after each of them committed to achieving net zero greenhouse gas emissions by 2050.

File photo taken in October 2020 shows a coal-fired power plant in the city of Sendai in Miyagi Prefecture, northeastern Japan. (Kyodo)

In prior negotiations, at least one G-7 member has proposed achieving the target for decarbonizing the power sector earlier than 2035 agreed on in last year's G-7 ministerial meeting in Germany, the sources said.

In last year's post-meeting communique, the G-7 ministers said they "further commit to a goal of achieving predominantly decarbonized electricity sectors by 2035."

Japan is apparently reluctant about the new proposal on the back of its plan to keep relying on coal, which is estimated to account for around 19 percent in its energy mix in fiscal 2030, the sources said.

While Japan says it will gradually reduce coal power and pivot back to nuclear energy, it has not set out a path to completely wean itself from coal with most of the country's nuclear plants remaining offline due to stricter safety regulations introduced after the 2011 Fukushima nuclear disaster and local opposition.

Another focus at the upcoming ministerial meeting is the G-7 countries' commitment on promoting zero emission vehicles, including whether they will set a target for such vehicles' market share or even a timeframe for phasing out fossil-fuel vehicles.

Japan, whose domestic manufacturers have strengths in gasoline-electric hybrids and plug-in-hybrids, is at odds with some of the member countries after Tokyo at one point put forward a proposal to halve carbon dioxide emissions from automobiles by 2035 from 2000 levels.

Japan is aiming to reduce greenhouse gas emissions in the country by 46 percent by fiscal 2030 compared to fiscal 2013 levels. The pledge includes a 35 percent emission cut in the transport sector.

The G-7 groups Britain, Canada, France, Germany, Italy, Japan, the United States plus the European Union.