Hundreds of protesters are marching as Group of Seven leaders arrive in the French resort town of Biarritz.
Protesters planned to cross into Spain from the French border village town of Hendaye. As the march began, they held cardboard signs aloft with pictures of Earth, protesting against climate policies they blame on the world's G-7 countries.
French President Emmanuel Macron, the host, put the Amazon fires at the top of the agenda for the weekend meeting.
Japanese Prime Minister Shinzo Abe has arrived for the Group of Seven summit amid escalating tensions with South Korea.
South Korea canceled a deal to share military intelligence, mainly on North Korea, after a trade dispute between the two countries.
Relations between two countries, both allies of the US, are at their lowest point since they established diplomatic ties in 1965.
Abe's plane touched down in the French seaside resort on Biarritz on Saturday morning.
Germany says that impeding a trade deal between the European Union and South American trade bloc Mercosur won't help reduce the destruction of rainforest in Brazil.
On Friday, Group of Seven summit host French President Emmanuel Macron threatened to block the recently agreed trade deal with Mercosur, which also includes Argentina, Paraguay and Uruguay. Ireland joined in the threat.
German Chancellor Angela Merkel has made clear she shares Macron's concern about the fires. But her government said in an emailed response Saturday to a query about the threat to the Mercosur deal that its trade section "includes an ambitious sustainability chapter with binding rules on climate protection," in which both sides committed to implementing the Paris climate accord.
It added: "the non-conclusion (of the deal) is therefore from our point of view not the appropriate response to what is currently happening in Brazil."
German Chancellor Angela Merkel says the Group of Seven leaders "cannot be silent" in the face of fires sweeping parts of Brazil's Amazon and will call for everything to be done to stop fires in the rainforest.
Germany is backing French President Emmanuel Macron's call to discuss the fires at the weekend's French-hosted G-7 summit. Merkel said in her weekly video message released Saturday: "Emmanuel Macron is right — our house is burning, and we cannot be silent."
She said leaders are "shaken" by the fires and that they will discuss "how we can support and help there, and send a clear call that everything must be done so that the rainforest stops burning."
Amid a series of policy and trade disagreements, which she didn't address explicitly, Merkel said that "talking to each other is always better than about each other — and the G-7 is an excellent opportunity for that."
World leaders and protesters are converging on the southern French resort town of Biarritz for the G-7 summit.
French President Emmanuel Macron is the host of the summit, which begins Saturday and has emptied out the town famed for its beach on the last week of the summer break. He has downplayed any expectations of a unified front from the leaders of the Group of Seven democracies.
US President Donald Trump arrives later in the day. At last year's meeting, Trump left early and repudiated the joint statement from Air Force One.
At the top of the agenda are climate change - and especially the fires burning in the Amazon - and a global economy teetering on the edge of recession.