The extensive military force which could soon be in striking distance of Syria will have to outfox sophisticated Russian air defence radars.
"We have proof that chemical weapons, at least chlorine, were used, and that they were used by the Bashar al-Assad regime", the French president said in an hour-long midday TV interview.
In Berlin, Chancellor Angela Merkel said Germany would not participate in any military strike on Syria.
With increasing concerns about a US-Russia proxy war in Syria, Mr Macron insisted that "France will not allow an escalation or something that could damage the stability" of the region.
Kremlin spokesman Dmitry Peskov cautioned against "any steps which could lead to an escalation of tensions".
European Council on Foreign Relations senior policy fellow Julien Barnes-Dacey said it was hard to see how the west could produce a wider strategy for Syria that allows for meaningful impact and limits escalation.
The attack on the town of Douma on April 7 killed dozens of people, including children.
Moscow, which offers military support to the Syrian regime, has warned of a possible Russian response to a United States attack.
The Syrian government has denied the allegations.
"Of course, the chemical attack is what pushed us to agree" to a withdrawal from Douma, said high-ranking Jaish al-Islam member Yasser Dalwan.
Russian Federation has described the reports of a chemical attack as a "provocation" created to justify Western intervention against its ally, and accused militant rebels of fabricating it.
There was no official announcement by Damascus that its forces had retaken the town of Douma, located near the capital Damascus, from rebels.
Meanwhile, an worldwide chemical weapons watchdog organization said Thursday that its team is en route to Syria and will begin work Saturday to investigate the attack, the Organization for the Prohibition of Chemical Weapons said.