France convinced Trump to strike Syria: Macron

France persuaded US President Donald Trump to stay in Syria and launch airstrikes as punishment for an alleged chemical weapons attack, French President Emmanuel Macron said on Sunday.

Appearing in a two-hour live broadcast on French television BFM and online investigative site Mediapart, the 40-year-old leader said the US, Britain and France had "full international legitimacy to intervene" in order to enforce international humanitarian law.

The allies fired missiles early on Saturday at three chemical-weapons facilities in Syria to punish the regime for the alleged use of chemical weapons in the town of Douma.

"It was retaliation, not an act of war," Macron said in justifying the operation a day before the French parliament was set to debate it. The airstrikes marked Macron's biggest foreign policy yet. Nearly a year into his term, the new president declared France the most active country on the diplomatic field and at the United Nations.

"Ten days ago President Trump wanted the United States of America to withdraw from Syria. We convinced him to remain," he said, speaking in the majestic room of Chaillot National Theater.

He said France now wants to involve Western powers, Russia and Turkey in a new diplomatic initiative to find a sustainable political solution in Syria.

Macron, due to make a state visit to the US next week and Russia next month, also offered to play the role of intermediary between Moscow and Washington, whose relationship has been on edge over the chemical weapons attack and amid allegations that Russia tried to interfere in the US 2016 presidential election.

The Syrian conflict began when the Baath regime, in power since 1963 and led by Assad, responded with military force to peaceful protests demanding democratic reforms during the Arab Spring wave of uprisings, triggering an armed rebellion fuelled by mass defections from the Syrian army.

According to independent monitors, hundreds of thousands of civilians have been killed in the war, mostly by the regime and its powerful allies, and millions have been displaced both inside and outside of Syria. 

The brutal tactics pursued mainly by the regime, which have included the use of chemical weapons, sieges, mass executions and torture against civilians have led to war crimes investigations.