Macron said Saturday's joint US, French and British air strikes on Syria were not a declaration of war on Bashar al-Assad's regime but legitimate action to force it to stop using chemical weapons.
Western powers say chlorine and possibly sarin were used in a 7 April attack in the town of Douma, just east of the capital Damascus, which killed dozens of people.
Macron said it was important to send a signal to the world that the use of chemical weapons would not go unnoticed.
But, he added, France is now putting together a diplomatic proposal for peace in Syria and he would still be visiting Moscow in May, although Russia is Assad's key ally and criticised the attack.
He also said he had steered Trump towards limiting air strikes to chemical weapons site and convinced him to keep US troops in Syria, despite the US president's earlier declaration that they would be pulled out.
Shortly after the interview aired, the White House said the US mission in Syria "had not changed" and that Trump still wants US forces to come home as quickly as possible.
Questioned as to why the air strikes went ahead without the backing of the United Nations Security Council, Macron said the action had been agreed by three of its permanent members adding that it was justified as Syria had not respected a 2013 UN resolution under which it promised to destroy its chemical weapons. Macron is also having to deal with industrial unrest here in France.
Strikes, pensioners, taxes
He acknowledged that his reform programme is causing friction, particularly in the French state railway operator, the SNCF, where unions have declared three months of rolling strikes but also in universities and amongst pensioners, who are up in arms about what they see as unfair tax increases.
Macron said he was obviously aware of the anger but would nevertheless press ahead with the reforms.
The president's advisors say he has little choice, as to give in to the strikers after only a year in office would seriously undermine any future efforts to modernise the country.
Call him Mr President
The interview itself, which was more rough-and-tumble than the usual presidential appearances, has aroused a certain controversy in political circles.
Journalists Edwy Plenel, of Mediapart, and Jean-Jacques Bourdin, of BFMTV, were accused of "caricaturing" Macron's policies by Marc Fresneau, of the Modem party, which is part of the ruling coalition.
Nice mayor Cristian Estrosi, a member of the right-wing Republicans, accused them of "trying to diminish the presidential function", while far-right MP Gilbert Collard asked "Would it take the skin off their mouths to say 'Monsieur le Président' just once out of respect for our institutions and our country?"
Former Socialist presidential candidate Benoït Hamon was impressed, however, finding the format "a lot better than the usual indulgent and conniving exercises", while the hard left's Jean-Luc Mélenchon called it "incredible", adding "You're not listening to the answers, you're waiting for the questions."
The interview was watched by 3.8 million people.
Read our summary of the press reactions here.