World leaders gather for G7 summit in France

  World leaders gather in Biarritz, France for the annual summit of the G7 nations

World leaders have gathered in France for the G7 summit, a meeting that European Council President Donald Tusk said will be a "difficult test of unity and solidarity" due to deep divisions over a range of issues including trade and climate change.

The annual gathering of the G7 nations, some of the world's key industrial countries, kicked off on Saturday in the French coastal town of Biarritz. Thousands of anti-G7 protesters rallied in the nearby town of Hendaye as the leaders from Britain, Canada, Germany, Italy, Japan and the United States descended on Biarritz.

The three-day summit is taking place against the backdrop of an escalating trade war between the US and China, Britain's impending exit from the European Union, growing tensions between the US and Iran over Tehran's nuclear programme and global concern over fires ravaging the Amazon rainforest in Brazil.

Speaking before the summit, Tusk appealed for unity.

"It is increasingly difficult, for all of us, to find common language and the world needs more of our cooperation, not less," he said.

"This may be the last moment to restore our political community."

French President Emmanuel Macron, the host of this year's summit, said he wants the heads of G7 nations to focus on the defence of democracy, gender equality, education and the environment. He also invited Asian, African and Latin American leaders to join them for a global push on these issues.

In a televised speech before the summit, Macron said he hoped to find common ground with US President Donald Trump, who acrimoniously ended last year's G7 meeting in Canada, leaving the gathering and rejecting the final communique, an agreed-upon statement released by all members.

Shortly after Trump's arrival, Macron hosted the US leader for a two-hour unscheduled lunch.

"So far, so good," Trump told reporters, hailing his friendship with Macron. "We'll accomplish a lot this weekend and I look forward to it."

Macron listed foreign policy issues the two would address, including Libya, Syria and North Korea, adding that they shared the same objective of preventing Iran from obtaining nuclear weapons.