US president Donald Trump is set to confront the consequences of his preference for going it alone in an interconnected world as he heads into a summit of global economic powers.

The Group of Seven (G7) nations are gathering in the French beach resort town of Biarritz at one of the most unpredictable moments in Mr Trump’s tenure, as his public comments and decision-making become increasingly erratic and acerbic.

Mr Trump, growing more isolated in Washington over his pugnacious ways, faces an even icier reception on the world stage, where a number of geopolitical challenges await.

Anxiety is growing over a global slowdown and new points of tension with allies are opening on trade, Iran and Russia.

With fears of a financial downturn spreading, increasing the need for cooperation and collective response, Mr Trump arrives having ridiculed Germany for its economic travails.

But the American leader may well need German chancellor Angela Merkel and others to help blunt the force of China’s newly aggressive tariffs on US goods.

Before leaving Washington on Friday, Mr Trump added fresh fuel to the raging trade war with China by declaring that US businesses with dealings in China are “hereby ordered” to begin moving home.

There was no immediate explanation of just what he expected or what authority he had to make this happen. He also slapped higher levels of tariffs on Chinese imports.

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A portrait of G7 leaders is drawn into the sand over the headline ‘Turn the tide for Gender Equality’ in Biarritz, France (AP)

“Tariffs are working out very well for us,” Mr Trump told reporters as he departed the White House for France. “People don’t understand that yet.”

The president earlier in the day made light of a sharp drop in the financial markets in reaction to his latest trade actions, with a tongue-in-cheek tweet speculating that the Dow’s plunge could be tied to the departure of a lower-tier candidate in the race for the Democratic presidential nomination.

In recent days, Mr Trump has sent mixed signals on a number of policy fronts.

At one point, he moved to de-escalate the trade conflict in order to ease the impact on consumers during the holiday shopping season.

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Mr Trump speaks with reporters as he walks to Marine One on the South Lawn of the White House (AP)

At another, he flip-flopped on the need for tax cuts to stimulate an economy that Mr Trump publicly insists is rocketing.

Feeding Mr Trump’s anxiety, aides say, is his realisation that the economy – the one sturdy pillar propping up his bid for a second term in office – is undeniably wobbly.

Now the president who has long eschewed multilateralism hopes to use his time in Biarritz to rally global leaders around the need to do more to promote economic growth.

Before arriving in France, he engineered a late change to the summit agenda, requesting a working session on global economic issues.

For the world leaders, it was the latest example of unpredictability from Mr Trump. After two-and-a-half years of a turbulent presidency, traditional American allies have come to expect the unexpected – and increasingly look elsewhere for leadership.

“They have figured out how to deal with this president,” said Jon Alterman, a senior vice president at the Centre for Strategic and International Studies (CSIS).

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Commentators have noted how the French president has looked to provide global leadership in the vacuum left by Mr Trump (AP)

“I think what we’re going to see out of this summit is, on the one hand, an effort by countries and the leaders to align with the president, but also an understanding that we’ll have to do more without the US president.”

The annual G7 summit has historically been used to highlight common ground among the world’s leading democracies.

But in a bid to work around Mr Trump’s impulsiveness, French president Emmanuel Macron has eschewed plans for a formal joint communique from this gathering.

Last year’s summit, hosted by Canadian prime minister Justin Trudeau, ended in acrimony after Mr Trump thought his Canadian counterpart had slighted him after he had departed.

Mr Trump then tweeted insults at Mr Trudeau from aboard Air Force One as he flew to a summit with North Korea’s Kim Jong Un and withdrew his signature from the statement of principles that all seven nations had agreed to.

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The previous G7 summit saw an unseemly spat between Justin Trudeau and Mr Trump (AP)

At his first G7 summit in 2017, Mr Trump’s strong feelings against climate change roiled the gathering in Italy.

Mr Trump has made his “America first” priorities clear at every turn.

At a recent campaign rally in New Hampshire, the crowd roared with approval when Mr Trump declared: “I’m the president of the United States of America. I’m not the president of the world.”

Addressing the global slowdown is not the only pressing challenge that Mr Trump has discovered requires multilateral action.

For more than a year, his administration has struggled with persuading European leaders to repatriate captured fighters from the Islamic State. To date his entreaties have been met with deaf ears.

Mr Alterman and Heather Conley, the Europe expert at CSIS, both said Mr Macron appeared to be trying to fill the void left by Mr Trump on the world stage, noting the French leader’s recent efforts to try to reduce tensions between the US and Iran.

Many of the summit proceedings will take place behind closed doors, in intimate settings designed for the leaders to develop personal relationships with one another.

Mr Trump, White House aides said, is especially looking forward to his sit-down with new UK Prime Minister Boris Johnson.

On the margins of the annual gathering, Mr Trump has scheduled individual meetings with several of his counterparts, including Mr Macron, Mr Trudeau, Mrs Merkel, Japanese prime minister Shinzo Abe and Indian prime minister Narendra Modi.

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A number of protests have taken place nearby the French town already (AP)

Also on the agenda will be the clashes between police and pro-democracy protesters in Hong Kong; Iran’s renewed nuclear enrichment and interference with shipping in the Strait of Hormuz; and the Islamic State prisoners who are currently imprisoned by American-backed Kurdish forces in Syria.

Increasingly fearful of an economic slowdown’s potential to diminish his 2020 electoral chances, Mr Trump is expected to press his fellow leaders about what can be done to spur growth in the US and abroad, as well as to open European, Japanese and Canadian markets to American manufacturers and producers.

Mr Trump has imposed or threatened to impose tariffs on all three markets in his pursuit of free, fair and reciprocal trade.

It is unclear what substantive steps could be taken by the leaders to address the global slowdown, and much of that discussion stands to be dominated by disagreements on Mr Trump’s trade policies.

While on French soil, Mr Trump also intends to raise with Mr Macron and the other leaders the issue of a digital services tax that France has imposed on major technology companies like Google and Facebook, despite Mr Trump’s threats to slap back with retaliatory tariffs on French wine.

The Trump administration says the tax targets and discriminates against US businesses.

As he headed for France, Mr Trump got in a dig at the host nation, saying of the tax: “It’s very unfair. And if they do that, we’ll be taxing their wine or doing something else.”