German Chancellor Angela Merkel urged Group of Seven (G7) leaders to commit to tough goals to cut greenhouse gases at the final day of their summit in the Bavarian Alps on Monday.
Merkel, once dubbed the "climate chancellor", hopes to revitalize her green credentials by getting the G7 industrial nations to agree specific emissions goals ahead of a larger year-end United Nations climate meeting in Paris.
Climate change topped the agenda for Monday's sessions, at which the leaders were also set to discuss combating epidemics and other health issues, the fight against terrorism from Boko Haram to Islamic State, and African development.
In a boost for Merkel's push to combat global warming, Japan said on Sunday it would favor the G7 countries setting their own target for reducing carbon dioxide emissions.
U.S. President Barack Obama kept his counsel on the climate issue on Sunday, the first day of the summit, when leaders presented a united front in facing Russian over the Ukraine conflict and discussed the global economy.
Japan and Canada were regarded before the summit as potential hold-outs on the climate issue, diplomats and environmental campaigners said.
French President Francois Hollande, who will host a U.N. summit on fighting climate change at the end of the year, was also looking for an ambitious commitment from the G7 to ending their dependence on fossil fuels by mid-century.
He was also seeking a financial commitment to aiding poorer countries to transform their energy sectors so they can reduce carbon emissions.
But it was not clear if Canadian Prime Minister Stephen Harper would accept a specific G7 goal.
"Canada supports an agreement in Paris that includes all GHG (greenhouse gas) emitting countries," Stephen Lecce, spokesman for Harper, told Reuters in an email.
The green lobby is hoping that Merkel will push for a pledge to phase out fossil fuels by 2050 ahead of the Paris meeting, which aims to agree on a successor to the Kyoto Protocol.
Greenpeace's head of international climate politics, Martin Kaiser, said the only way for the summit to be seen as a success is for the U.S., Japanese and Canadian leaders to "take their feet off of the throat of a climate agreement."
"This means an unequivocal commitment and support for competitive renewable energy technologies," he added.
The G7 leaders will meet so-called "outreach guests" – the leaders of Nigeria, Senegal, Ethiopia, Liberia, South Africa, Tunisia and Iraq – and hold final news conferences in the afternoon.