BIARRITZ, France — President Donald Trump arrived here Saturday for a summit with world leaders fixated on a trade war with China and eyeing another with Europe.

As Trump left the White House late Friday night, he told reporters that he has the authority to stop U.S. companies from doing business in China amid an escalating tariffs tit-for-tat between the two countries.

“I have the absolute right to do that,” Trump insisted.

Trump also said his trade war with China “is more important than anything else right now just about that we're working on.”

As the president spars with China, a move that threatens to drag down the U.S. economy, he arrives at the Group of Seven Summit angling to start another trade dispute with Europe.

Trump plans to turn up the volume on his accusations of unfair trade practices by America’s closest allies, a favored campaign talking point, according to senior administration officials.

And ahead of the meeting, Trump revived his attacks on Europe.

At a campaign rally in New Hampshire last week, he called out German Chancellor Angela Merkel and accused European countries of “killing us on trade.” At a fundraiser last week in the Hamptons, New York, he suggested that he may put a 100 percent tariff on French wine, according to a Bloomberg report.

As he was leaving the White House Trump was tepid about his relationship with the group of America's closest allies, calling the leaders he'll be sitting down with “mostly friends.”

Trump has a series of one-on-one meetings lined up Sunday with the world leaders.

As he arrived the summit's host, French President Emmanuel Macron, gave a televised speech laying out his priorities for the meeting.

He said one of his main goals will be to convince leaders that a global trade war is bad for all, but acknowledged that not all the leaders shared his view.

This image grab from footage taken and released by French television channel TF1 shows French President Emmanuel Macron delivering a speech in Biarritz on Saturday. HANDOUT / AFP - Getty Images

Drawing attention to the fires raging in the Amazon rainforest, Macron said the world is at a tipping point.

“I promise you, in your name, to do my maximum to get those to agree,” Macron said in a direct address to the French people.

At an impromptu photo opportunity over lunch, Macron said they planned to discuss crises in Syria, North Korea, Ukraine and Iran, and acknowledged the disagreement Trump has with the other leaders on climate change.

"We know the divergences we have on climate," he said. "But our cooperation will be to reduce carbon emissions."

President Donald Trump has lunch with French President Emmanuel Macron at the Hotel du Palais in Biarritz on Saturday. LUDOVIC MARIN / AFP - Getty Images

Of Macron, Trump said they "have a lot in common” and that "once in a while we go at it just a little bit, not very much."

He wants to look tough on China to appease his base of supporters, but he risks throwing the U.S. into a recession ahead of next year's election, undercutting one of his main selling points for why he deserves a second term.

Trump said Friday he would be putting a new round of tariffs on Chinese goods in retaliation for new Chinese tariffs on $75 billion in U.S. goods. He once again said Chinese policy has caused billions of dollars of lost revenue to U.S. companies. The country, he said, "has been taking advantage of the United States on Trade, Intellectual Property Theft, and much more."

Late Friday, the president tweeted that he has broad powers to regulate U.S. economic interests abroad, urging journalists to "try looking at the Emergency Economic Powers Act of 1977. Case closed!"

The International Emergency Economic Powers Act allows a president to prohibit most trade with a perceived foe "to deal with an unusual and extraordinary threat with respect to which a national emergency has been declared."

The law requires a president to explain his action to Congress, and it allows Congress to shut down the action. It was enacted to limit presidential power by further defining it and encoding congressional oversight.

The U.S. stock market fell sharply after China announced it would slap retaliatory tariffs on American soybeans, crude oil and cars. The Dow Jones Industrial Average closed the day down 623 points, or 2.4 percent.

The president in recent days has sought to calm fears about the economy, brushing off talk of a recession and defending his actions on China.

But despite his public reassurances, inside the White House there was growing acknowledgment that the U.S. needs to settle the standoff with China before it takes a bigger toll on the economy.