French president Emmanuel Macron has laid out a firm vision of global leadership in a speech to US Congress, rejecting “the illusion of nationalism” in a candid counterweight to Donald Trump’s appeals to put “America first”.

Opening a joint meeting of Congress, Mr Macron was courteous but firm, deferential but resolute as he traced the lines of profound division between himself and Mr Trump on key world issues: climate change, trade and the Iran nuclear deal.

A day after the French leader had put on a show of warmth and brotherly affection for Mr Trump at the White House, his blunt speech prising engagement over isolationism reinforced the French leader’s emerging role as a top defender of the liberal world order.

“We can choose isolationism, withdrawal and nationalism. This is an option. It can be tempting to us as a temporary remedy to our fears,” Mr Macron said.

“But closing the door to the world will not stop the evolution of the world. It will not douse but inflame the fears of our citizens.”

Emmanuel Macron as he is introduced before speaking to a joint meeting of Congress (Pablo Martinez Monsivais/AP)Emmanuel Macron as he is introduced before speaking to a joint meeting of Congress (Pablo Martinez Monsivais/AP)

Issuing a bleak warning, he urged against letting “the rampaging work of extreme nationalism shake a world full of hopes for greater prosperity”.

It was a marked shift from the simpatico Mr Macron of only a day earlier during his state visit at the White House.

In his first year as France’s president, Mr Macron has carefully cultivated as close a relationship to Mr Trump as any world leader can boast.

But addressing a joint meeting of Congress — an honour granted only occasionally to leaders of close US allies — Mr Macron confronted his differences with Mr Trump head-on.

As Mr Trump weighs pulling out of the 2015 Iran accord, Mr Macron made clear that France will not follow his lead.

“We signed it at the initiative of the United States. We signed it, both the United States and France,” Mr Macron said. “That is why we cannot say we should get rid of it like that.”

Mr Macron later told French reporters that he has no “inside information” on Mr Trump’s decision on the Iran deal but noted that it is clear the US president “is not very much eager to defend it”.

Mr Macron saved some of his most pointed comments during the speech on Trump administration policy on climate change, implicitly lamenting the president’s moves to withdraw from the global emissions pact reached in Paris.

Mr Macron said humans are “killing our planet” and added: “Let us face it: There is no Planet B.”

“On this issue, it may happen we have disagreements between the United States and France. It may happen, like in all families,” Mr Macron said. “But that’s for me a short-term disagreement.”

Asked by French reporters about his comments later during a visit to the Martin Luther King Jr Memorial, Mr Macron said with a smile that he does not expect Mr Trump to rejoin the Paris accord but does expect that America will.

Mr Macron’s hour-long speech to Congress, delivered in English, provoked obvious delight from congressional Democrats, who erupted repeatedly in cheers and standing ovations for the visiting Frenchman — a contrast to the mostly silent reaction from Republicans in the House chamber.

But it was not all criticism from Mr Macron. He sought to showcase the historic bond between the US and France, touting the two allies’ “constant attachment to freedom and democracy”.

Yet he also mentioned “fake news,” a point of contention between Mr Trump and others, and warned that lies disseminated online are threatening freedoms worldwide.

Donald Trump and Emmanuel Macron kiss during a State Arrival Ceremony on the South Lawn of the White House (Andrew Harnik/AP)Donald Trump and Emmanuel Macron kiss during a State Arrival Ceremony on the South Lawn of the White House (Andrew Harnik/AP)

In friendly fashion, he recounted trans-Atlantic links from the earliest days of the United States.

Mr Macron talked about a meeting between Ben Franklin and the French philosopher Voltaire, “kissing each other’s cheeks”.

In an apparent reference to his affectionate rapport with Mr Trump this week, Mr Macron mused: “It can remind you of something.”