Saint-Jean-de-Luz, France (CNN) Even after President Donald Trump claimed all was well at the Group of 7 summit, which got underway Sunday on France's Atlantic coast, there was evidence of rancor behind the scenes.

Trade disputes spilled into the open, even with a new friend. After Trump appeared to soften his stance on China tariffs, aides swooped in to explain he wasn't backing down.

Privately, American officials griped the yearly gathering is being orchestrated to isolate the United States. Aides to other leaders shrugged off the accusation, saying Trump's go-it-alone views on climate change, Russia and trade were his own doing.

In the middle of it all, Iran's foreign minister turned up unexpectedly for talks with his French counterpart, furthering the impression that Trump -- who withdrew from the Iran nuclear deal that his European counterparts are working to salvage -- is a man apart.

It all added up to a fraught beginning to the G7, which ordinarily proceeds with friendly displays of partnership and without the obvious level of discord playing out at the elegant seaside resort Biarritz.

Already, the near-consensus among Trump's foreign counterparts that tariffs on China are causing the global economy to slump appeared to weigh on the President. He told reporters he's had his own misgivings.

"I have second thoughts about everything," he said, without saying what he might be reconsidering.

Hours later, aides insisted the President had trouble hearing the question and that Trump remains staunch as ever in his tariff regime.

"He didn't exactly hear the question. Actually what he was intending to say is he always has second thoughts and actually had second thoughts about possibly a higher tariff response to China," Trump's chief economic adviser Larry Kudlow said Sunday on CNN's "State of the Union."

"It was not to remove the tariff," he said.

But that wasn't Trump's only turnabout. He also softened his threat to force US companies out of China -- despite insisting a day earlier he was able to do it using his executive powers.

"I have no plan right now. Actually, we're getting along very well with China right now. We're talking," Trump said.

Kudlow confirmed there's "nothing now in the cards" to exert executive authority that would bar US firms from doing business in China -- but wouldn't rule out the possibility in the future.

"Ultimately we do have such authority but it is not going to be exercised presently," he said.

The hurried clean-up reflected the precarious position Trump has adopted as he meets with world leaders. Even as they lobby against the tariffs, which they blame for various economic woes, Trump has insisted the tariffs are working and must remain in place.

That's caused considerable angst at the summit, where Trump's counterparts had gripped themselves for confrontation before his arrival.

Even an impromptu lunch Saturday between Trump and his host, Emmanuel Macron, appeared to be an attempt by the French President to corner Trump into a discussion of climate change and trade.

Trump insisted the meal was their best meeting ever. But afterward, American officials complained the session materialized without warning and amounted to a first attempt by Macron to mold his summit around issues that will divide Trump from other leaders.

The surprise announcement that Iranian Foreign Minister Mohammad Javad Zarif was in Biarritz meeting with his French counterpart only fueled the notion of a summit on France's terms. Zarif was not expected to meet any American officials during his visit to France, which was first discovered when an Iranian plane was spotted on the tarmac here.

US officials say they weren't given significant advance warning that Zarif would be in Biarritz. One administration official called Zarif's unexpected arrival at the G7 a "curveball," but claimed it was Macron's prerogative to invite him.

Macron alerted Trump and other leaders that Zarif would be in France during the Saturday evening dinner with G7 leaders. But US officials weren't aware of the plans in the lead up to the summit, according to two senior administration officials.

Trump has chided Macron in the past for sending "mixed signals" to Iran; he said Sunday he hadn't discussed any joint message from the G7 to Tehran during the summit after the French presidency suggested Macron would deliver such a statement.

Asked about Zarif's presence in Biarritz on Sunday, Trump offered only a curt "no comment."

Less contentious was a Sunday morning breakfast with Boris Johnson, the newly installed British prime minister in whom Trump sees a more natural ally.

"You know who this is?" Trump asked reporters, gesturing toward Johnson, as the men descended a grand staircase at Trump's hotel. "He's going to be a fantastic prime minster."

Later, over a meal of scrambled eggs and veal sausage, Trump acknowledged he was more aligned with Johnson than his predecessor in Downing Street, Theresa May.

"He needs no advice. He's the right man for the job. I've been saying that for a long time. It didn't make your predecessor happy," Trump said.

"You're on message there," the enthusiastic prime minister replied.

In Johnson, Trump has at last found a leader of a major US ally with whom he is politically aligned, in style if not substance . His breakfast meeting with the British Prime Minister was the highlight of the G7 agenda for Trump.

US President Donald Trump and Britain's Prime Minister Boris Johnson arrive for a breakfast meeting during the G7 on Sunday.

Open differences

Still, Trump remains deeply unpopular across Europe, including in the UK. And similarities in style don't necessarily reflect deep policy agreements, except on the issue of Brexit.

That was in evidence Sunday as Trump claimed during his breakfast that he'd heard no complaints about the trade tiffs.

"I haven't heard that. I think they respect the trade war. It has to happen," Trump said.

Johnson was quick to correct him.

"Just to register a faint, sheeplike note of our view on the trade war: we're in favor of trade peace on the whole," he said. "We think that on the whole, the UK has profited massively in the last 200 years from free trade and that's what we want to see. So, that's what we're keen to see. We don't like tariffs on the whole."

It was an early sign of what was to come at the G7: leaders nearly uniformly opposed to Trump's tariffs, which have been blamed for dragging down economies and throwing equity markets into turmoil.

Trump sought to dispel the notion on Sunday that he was feuding with his G7 counterparts, despite their open differences on his use of tariffs or his environmental record.

"We are having very good meetings, the Leaders are getting along very well, and our Country, economically, is doing great - the talk of the world!" he wrote on Twitter.

Alongside Japanese PM Shinzo Abe -- with whom he announced an "agreement in principle" on a new trade package -- Trump said he'd been "treated beautifully" since his arrival in France.

But that ray of optimism was belied by a caught-on-camera moment from Johnson, who was overheard praising Macron for his handling of a "difficult" dinner with the US President and the other leaders the evening before.

"Bien joué," he said, "well played. You did very well last night, my God. That was a difficult one. You did brilliantly."

Trump later told reporters that a focus of discussion at the dinner was the prospect of allowing Russia back into the G7.

Excluded after its incursion into Ukraine, Russia hasn't participated in the yearly gathering since 2014.

"I think it's a work in progress. We have a number of people that would like to see Russia back," he said. "I think it would be advantageous to many things in the world. I think it would be a positive. Other people agree with me and it's something that we're discussing."

Trump wouldn't say who agreed with him. Most European leaders have ardently maintained that Russia must not be allowed back as its invasion of Ukraine persists.

Trump's description of an amicable summit was also undercut by complaints from US officials that the meeting was being orchestrated by its French hosts to highlight issues that benefit the French president and demonstrate Trump's isolation.

"The G-7 is in danger of completely losing its way," Kudlow wrote in an op-ed in the Wall Street Journal as leaders were gathering in Biarritz.

French President Macron and US President Trump at a G7 meeting on Sunday.

Second thoughts on dispute

Other American officials traveling with the President said they believed Macron was intentionally adding sessions to the summit that are meant to pit Trump against his fellow leaders.

Trump himself had griped before the summit that like past gatherings, the G7 was overly focused on issues like plastics in the ocean and global women's empowerment -- and not the global economy, on which the organization was originally founded.

At the last minute, US officials added a Sunday morning session on the economy in an effort to realign the agenda. But Trump has viewed the added meeting as an opportunity to brag about the American economy -- and his role in it -- to nations where growth is slowing.