Emmanuel Macron reckons he has found the best way of dealing with Donald Trump. It involves acceptance that the US president’s mind will not be changed where a campaign promise is involved. But on everything else – keep talking.

Macron’s method is about to be put to the test once more as Trump arrives on Saturday to join the G7 summit of the world’s major industrialised democracies in Biarritz. So far, the results have been thin at best.

It is hard to pinpoint a policy on which the French president changed has his counterpart’s mind, and even before he left Washington Trump was needling his host, accusing Macron of trying to speak for the US in talks with Iran, and falsely claiming that the French president agreed with him that Russia should be readmitted to the club.

But Macron has not given up on dialogue. The two leaders spoke early this week for an hour by phone, agreeing that in Biarritz they would discuss “all topics, with no taboos”.

Macron told reporters this week: “It’s very simple with President Trump: if he has made a campaign promise, you won’t change his mind. Because his driving force is American politics. I respect and understand that. It’s clear … your capacity to convince him to go back on them is weak.”

Q&A What is the G7? Show Meeting regularly since 1976, the G7 is made up of seven countries: Canada, France, Germany, Italy, Japan, the UK and the US. Between them, the countries represent around half of the world’s GDP, and the group’s main purpose is to provide a forum for discussing world economic stability. The first meetings grew out of a series of summits to deal with the 1973 oil crisis. G7 summits take place annually, with the host nation rotating between the members. Summits are usually attended by leaders, finance ministers and central bank governors. As well as the seven nations, the meetings are also usually attended by leaders from the European Union, and representatives from international financial institutions including the International Monetary Fund and the World Bank. As well as the high-profile summits, the finance ministers from the G7 also meet on a regular basis several times a year. Between 1998 and 2014 the grouping was known as the G8, and also included Russia among its members. However, Russia was expelled in 2014 following the annexation of Crimea.

Martin Belam

The French president said that although “we don’t think the same things about the world order, or have the same objectives”, the key was to maintain a constant intensity of dialogue with Trump, to avoid disagreements piling up.

“My method is to talk, to say things without compromise, and then to try to take up the points we converge on and not give in on the things we disagree on,” Macron said, noting Trump had visited France more than any other country.

Hosting Trump at a multilateral summit is likely to bring special challenges. Such high-level meetings were once seen as a sure way to enhance the reputation of the host nation, but that was in the pre-Trump era.

Nowadays summit planning is an exercise in damage limitation. At last year’s G7 in Canada, Trump upset months of difficult negotiation and orchestration with a fit of pique on his way out of the Quebec venue, disowning a consensus communique and denouncing the host, Justin Trudeau, as “dishonest and weak” over some perceived slight.

One lesson Macron has drawn from the Quebec fiasco was to do away with a final communique, robbing commentators of an easy benchmark to declare the summit a failure.

“On the main issues we expect the G7 not to produce solutions for everything, not to produce a fully comprehensive statement,” one official said. “That’s probably one way to avoid the same situation we had in Canada last year.”

Lowering expectations is not without its costs. The formal expression of solidarity of the “western world”, in the face of crisis and uncertainty, is a principal purpose of G7 summits.

In Biarritz there will be a variety of joint statements on different issues such as inequality, the climate crisis, and the global economy on a sliding scale of formality. But such crafty choreography may well not be enough to cover all the cracks in the democratic camp, one gaping fissure in particular.

Trump arrives in Biarritz on Saturday in an especially unmoored and cantankerous mood as darkening clouds of recession gather over his re-election bid.

He has abruptly called off a state visit to Denmark after its government refused to entertain his proposal it sell Greenland to the US. He has been referring to himself in ever more messianic terms.

It has been traditional for the G7 to refer to itself as a “family” of nations, but the summit is not some convivial gathering where the dotty uncle can be left in the corner to grumble and rant. Trump heads the world’s biggest economy and its mightiest armed forces. He influences a growing flock of authoritarian leaders around the world who have set themselves up as the counterweight to the pro-trade, pro-democracy ethos that has previously underpinned the G7. If not handled with extreme care, Trump has the power to detonate what remains of “western” unity at an increasingly dangerous juncture.

Some governments have sought to captivate him through flattery and pandering, and cultivation of the president’s family. Saudi Arabia, Israel, North Korea and China have all treated him like an emperor. Trade tensions have soured the relationship with Beijing, but his red carpet welcome in 2017 has left him convinced he shares a transcendent bond with Xi Jinping.

European allies have had less success playing to Trump’s vanity.

Despite Trump’s constant jibes on Twitter, Theresa May also tried to win him over with the full pageantry of a state visit, despite his toxic unpopularity in the UK, but he still threw her under a doubledecker bus with the contempt he showed for her desperate efforts to clinch a Brexit deal.

Macron wowed him with a Bastille Day military parade in 2017, has kept up a constant dialogue with him, and has tried to avoid any direct criticism. But it is hard to identify any issues on which Macron has changed Trump’s mind.

He claimed success in persuading the US president not to pull his troops out of Syria too early, but Trump’s own top officials and generals have been making the same argument, and ultimately it has been an agreement with Turkey over a safe zone in northern Syria that has kept a residual US force in place.

The French approach in Biarritz is to aim at making the proceedings less reliant on the president and his moods. Not only has Macron done away with the rigidity of the final communique, he has sought to dilute Trump’s role by inviting lots of other guests to the party. African presidents have been asked for a session devoted to their continent, and leaders from India, Chile, Spain and Australia have been invited for sessions on climate, biodiversity, the oceans and digital technology.

It is a recognition that the world’s most pressing problems can no longer be fixed by an exclusive club of wealthy nations, but also an admission that, in the age of Trump, the G7 countries now have less in common.