Macron invited Trump to be his guest of honour at the Bastille Day celebration, which featured French and American troops marching down the fabled Champs-Elysees in Paris, opening to a flypast by two US F-22 stealth fighters and climaxing in a roaring pass by French jets.
Trump, 71, was frequently on his feet and applauding, while he and Macron again looked at ease in each other's company, leaning in to chat and touching each other on the shoulder.
“Nothing will ever separate us,” Macron said during a speech at the end of parade, adding that Trump's presence was “the sign of a friendship across the ages” between their countries.
The Paris parade this year marked the centenary of the United States entering World War I in 1917 and featured 63 planes, 29 helicopters, 241 horses and 3,720 soldiers, including US troops dressed in the brown uniform and gaiters of the Great War.
“It was a great honor to represent the United States at the magnificent #BastilleDay parade,” Trump wrote on Twitter after his departure, which featured another long and muscular handshake between the men. “Congratulations President @EmmanuelMacron!” he added.
But the celebrations were also tinged with mourning, one year on since a jihadist massacre in the Mediterranean city of Nice where a man drove a truck into a crowd, killing 86 people.
Macron, 39, rolled out the red carpet for Trump's two-day visit, hoping to improve relations and persuade the US president to change his mind about withdrawing from the global Paris agreement on climate change.
Trump said cryptically after their talks on Thursday that “something could happen with respect to the Paris accord… but we will talk about that over the coming period of time.”
Trump had appeared isolated at a meeting of world leaders last weekend in Germany over his decision to withdraw the US from the Paris global climate change agreement and his protectionist stance on trade.
The warm body language between him and Macron seemed at odds with broader concerns about the transatlantic relationship since Trump's election victory in November last year.
The two men enjoyed a “dinner between friends” on Thursday at a Michelin-starred restaurant on the Eiffel Tower.
Joined by their wives Brigitte and Melania, they tucked into beef with truffle sauce and warm strawberry and yogurt sorbet, with one of the most celebrated views in the world as their backdrop.
Trump also said Thursday that the bond between the US and France, as well as the friendship between him and Macron, was “unbreakable.”
Despite their differences on climate change and trade, the two leaders focused on their close cooperation on fighting the Islamic State group in Syria and Iraq during their talks.
City in mourning
Bastille Day commemorates the storming of the Bastille prison in 1789 – the start of the French Revolution and a turning point in world history.
This year's celebrations are tinged by memories of last year's bloodbath in Nice, when a Tunisian man drove a truck into crowds of families following a fireworks display.
In less than three minutes, 86 people including 15 children were crushed to death and another 450 were injured. Of the dead, 37 were foreigners of 19 different nationalities.
Instead of fireworks this year on the Promenade des Anglais seafront boulevard, there will be candles, a memory book and a solemn speech by Macron.
The Islamic State group claimed responsibility for last year's attack by one of its “soldiers” — 31-year-old Tunisian Mohamed Lahouaiej Bouhlel, shot dead at the end of his rampage – though no direct link has been found.
The attack left a “gaping wound”, said local Emilie Petitjean, who lost her nine-year-old son and has been tasked by a victims' association with planning a ceremony on behalf of 76 families.
“It's a recognition. Everyone knows we have suffered. I don't expect to get better, but I expect Nice to be honoured,” she said.
France has been under a state of emergency since November 2015, when 130 people were slaughtered in a wave of coordinated violence across Paris, with French lawmakers voting last week to extend it for the sixth time.
More than 130,000 security and emergency service workers have been deployed to protect revellers during this year's Bastille Day celebrations, according France's interior ministry.
Terror attacks in France have killed more than 230 people since January 2015. Interior Minister Gerard Collomb says seven terror plots have been foiled since the start of this year.