Group of Seven nations are butting heads over the timeline for phasing out coal-fired power ahead of next weekend’s summit of top energy and environmental ministers.

Draft communique documents circulated before negotiations resume Tuesday show the European Union, the U.S. and Japan expressed reservations about a U.K. proposal to set a 2030 deadline for phasing out unabated domestic coal power generation. The language, which won France’s backing, also would have recognized the need to "cancel the pipeline of new global coal power generation projects,” and therefore have the G7 countries committing to end construction of new domestic coal-fired power plants and work with international partners to end similar efforts globally.

While Japan, the U.S. and EU indicated reservations, Germany offered alternative language that would have emphasized the goal of phasing out domestic unabated coal power generation "ideally by 2030” or "in the 2030s.” Japan, which hosts the G7 this year, has proposed reaffirming the commitment in last year’s G-7 leaders’ statement "to achieving a fully or predominantly decarbonized power sector by 2035.”