Macron hopes to convince G7 leaders to halt trade war and heal divisions

French president Emmanuel Macron has said he hopes to convince world leaders to pull back from trade war and heal growing divisions at the G7 summit in Biarritz, despite signs that will be a daunting task.

Related: Boris Johnson prepares for Biarritz balancing act with Donald Trump

The leaders of the major industrialised democracies gathered in the French Atlantic resort amid global crises, deep rifts within the group and increasingly erratic behaviour by Donald Trump.

“There is still no certainty whether the group will be able to find common solutions, and the global challenges are today really serious, or whether it will focus on senseless disputes among each other,” European council president Donald Tusk said in a strikingly dour assessment of the summit’s chances of success.

“The last years have shown that it is increasingly difficult for all of us to find common language when the world needs our cooperation more, not less. This may be the last moment to restore our political community.”

Those difficulties emerged just hours after Trump arrived in France, with US officials accusing the French president of focusing the summit on what they called “niche” issues such as climate change, gender equality and development in Africa. The topics were chosen specifically to appeal to Macron’s domestic audience and supporters, they said, according to multiple US media reports.

At an opening dinner of Basque cuisine in a 19th-century lighthouse, Macron was expected to seek consensus and potentially common action among guests including Tusk and the leaders of the US, UK, Germany, Canada, Japan and Italy.

“We are going to talk about the great conflicts: Iran, Syria, Libya and Ukraine,” Macron said.

He was also expected to raise the ecological catastrophe unfolding in the Amazon and the threat of global recession caused by tit-for-tat tariffs leading to full-blown trade wars.

Trump has been a common factor in all the crises, on which he is mostly at odds with other leaders. Before leaving for Biarritz, the American president imposed new tariffs on China and invoked a national security law in a threat to force US companies to stop doing business there.

Trump has so far resisted pressure from his fellow leaders to return to the 2015 nuclear deal with Iran, which he abandoned last year, leading to an accelerating rise in tensions in the Persian Gulf.

And running counter to a European effort to force Jair Bolsonaro to change policies on the Amazon contributing to deforestation and catastrophic wildfires, Trump has embraced the far-right Brazilian leader, sending him an encouraging tweet before leaving Washington.

“Our future Trade prospects are very exciting and our relationship is strong, perhaps stronger than ever before,” Trump wrote.

The US president is also at odds with other leaders on Russia, which was ejected from what was the G8 because of military aggression in Ukraine. Trump has repeatedly pushed for Russia to be allowed to rejoin.

“One year ago, in Canada, President Trump suggested reinviting Russia to G7, stating openly that Crimea’s annexation by Russia was partially justified,” Tusk said in remarks that were bitterly critical of the US president. “And that we should accept this fact. Under no condition can we agree with this logic.”

Clouds were also gathering over a potential spat with the EU over digital tax after Trump said he could decide to retaliate for France raising a levy on web companies such as Google by taxing French wines “like they’ve never seen before”.

The lack of unity has led Macron to abandon efforts to draft a comprehensive joint statement for the end of the summit. Some senior officials charged with planning the summit have not bothered to attend some preparatory meetings, according to two officials at the summit.

Before the opening dinner, Macron, Tusk, Germany’s Angela Merkel, new UK prime minister Boris Johnson and outgoing Italian premier Giuseppe Conte held a meeting in an effort to coordinate their positions.

Johnson, at odds with the EU over the terms of UK withdrawal, has also been courted by Trump, who called him on Friday “to discuss a range of foreign policy and trade issues”, the White House said.

Macron had an unscheduled lunch with Trump. After bumping into the US leader and his wife, Melania, in a hotel lobby shortly after they landed, he offered Trump a meal on an ocean-front terrace in order to prepare some of the summit’s thorniest issues. These included the war in Syria, the Iran nuclear treaty, Ukraine, the Amazon fires, the climate emergency and trade wars.

The leaders sat at a table adorned with flowers, Macron saying their priority was to discuss the stand-off with Iran, with “strong coordination” and “hard work” needed.

Trump at first appeared to be sitting arms crossed and frosty, but went on to praise his host and the beauty of Biarritz.

“We actually have a lot in common,” Trump said, adding that he and Macron had “been friends for a long time”. Trump admitted that at times he and Macron “go at each other a little bit” but said they had a “special relationship”.

He added: “So far, so good. The weather is perfect. Everybody’s getting along. I think we will accomplish a lot this weekend.”

The issue of how to bring Trump on board is a main concern among G7 diplomats. Macron had already scrapped the idea of a joint statement, after Trump pulled out of the joint statement last year in Canada, in a fury at prime minister Justin Trudeau.

Related: No-deal Brexit would shrink UK's global influence, say ex-ambassadors

Macron has acknowledged differences with Trump on the climate emergency but still hopes to find consensus on other issues and could give a joint press conference with the US president at the end of the summit.

“I want to convince all our partners that tensions, and trade tensions in particular are bad for everybody,” Macron said in a televised address.

He added: “We must succeed in reaching a de-escalation, stabilise things and avoid this trade war which is already taking place everywhere.”

Macron said G7 countries should “find new ways to launch real stimulus, stimulate growth”, and pointed at rock-bottom interest rates which he said should spur countries with budgetary room for manoeuvre to invest in education and job-creating initiatives.