Emmanuel Macron has claimed he has 'proof' that the regime of Bashar al-Assad launched a horrifying gas attack in Syria.

The French President suggested chlorine may have been used in the atrocity on Saturday that left at least 40 dead in the rebel-held town of Douma and prompted Donald Trump to consider launching airstrikes.

Assad denies carrying out the attack and Russia has accused aid workers of faking the incident.

But Macron said today: 'We have proof that chemical weapons were used last week, at least chlorine, and that they were used by the regime of Bashar al-Assad.'

Emmanuel Macron has claimed he has 'proof' that the regime of Bashar al-Assad launched a horrifying gas attack in Syria

The U.S. has maintained its threat of rocket attacks in response to Syrian dictator Bashar al-Assad's sickening chemical attack on the rebel-held town of Douma on Saturday

Macron added that he was in daily contact with US President Donald Trump and that they would decide on their response 'at a time of our choosing, when we judge it to be the most useful and the most effective.'

The French leader, who had made the use of chemical weapons in Syria a 'red line', said one of his aims in Syria was to 'remove the regime's chemical attack capabilities'.

But he repeated that he wanted to also avoid 'an escalation'.

'France will in no way allow an escalation or anything that would harm regional stability, but we cannot allow regimes that believe they can act with impunity to violate international law in the worst possible way.'

Meanwhile, Syrian President Bashar al-Assad warned on Thursday that threats of Western military action in response to an alleged chemical attack would only lead to further chaos in the region.

'These voices, and any possible actions, will only contribute to further destabilisation in the region,' Assad said.

It comes as US President Donald Trump said an attack on Syria could take place 'very soon or not so soon at all!'

The president made the comments a day after he had warned Russia to 'get ready' for a missile attack on its ally Syria, suggesting imminent retaliation for last weekend's chemical weapons attack.

Syrian President Bashar al-Assad (pictured today with Ali Akbar Velayati, an adviser to Iran's Supreme Leader Ayatollah Ali Khamenei) warned on Thursday that threats of Western military action in response to an alleged chemical attack would only lead to further chaos in the region

But on Thursday, Trump wrote that he: 'Never said when an attack on Syria would take place.'

Russian lawmakers have warned the United States that Moscow would view an airstrike on Syria as a war crime and that it could trigger a direct U.S-Russian military clash.

Russia's ambassador to Lebanon said any missiles fired at Syria would be shot down and the launching sites targeted - a stark warning of a potential major confrontation.

Trump suggested Monday he had little doubt that Syria was to blame, but neither he nor other administration officials have produced hard evidence.

This is in contrast to an incident one year ago in which the U.S. government had video and other evidence of certain aspects of an actual attack by Syrian aircraft, which involved the use of sarin gas. Trump responded then by launching dozens of Navy cruise missiles at a Syrian airfield.

The U.S., France and Britain have been in extensive consultations about launching a military strike as early as the end of this week, U.S. officials have said.

Russia celebrates as Assad takes control of rebel town Syrian government forces have seized 'full control' of the city of Douma less than a week after the alleged chemical weapons attack that killed dozens of civilians, Russian state news reports. Russian military police unites were seen joining in celebrations on the streets of Douma, eastern Ghouta, as government soldiers raised the Syrian flag, in video footage published by Kremlin-funded news. Rebel fighters in Douma surrendered after a series of ferocious assaults by President Bashar al-Assad's forces, aided by Russia under a massive bombardment. Gathering: Hundreds of people took to the streets in Douma after the surrender of the rebels as Syrian government forces seized control 'A state flag hoisted on the Douma building heralded control over this settlement and, hence, over entire Eastern Ghouta,' Major-General Yuri Yevtushenko, head of the Russian Peace and Reconciliation Centre in Syria, was quoted as saying by Russian news agencies. The Jaish al-Islam group in Douma agreed on Sunday to withdraw, hours after a suspected chemical weapons attack on the town that has raised the prospect of U.S. strikes. Human rights activists and aid workers in Syria reported that more than 40 people were killed when two bombs, allegedly chemical weapons, were dropped on Douma on Saturday afternoon. Hospitals allegedly saw more than 500 patients admitted with symptoms of exposure to chemicals such as foaming at the mouth, asphyxiation and blue lips. The Syrian government and Russia have called reports of the attack bogus. Government control: Russian military police unites were seen joining Douma residents in celebrations on the streets Local residents held up large Syrian flags and danced in the street on Monday Got to go: A child from Douma cries as his family arrives in Aleppo last night Russian military police were deployed in Douma on Thursday in accordance with the rebel surrender deal, Russia's RIA news agency reported. Some 40,000 people, including thousands of rebels and their families, are being forcibly evacuated from Douma and other opposition areas in northern Syria under the agreement. On Wednesday, a top official from Iran, Assad's other main ally, toured eastern Ghouta and vowed to stand by Syria in the face of 'any foreign aggression'. 'Syria's enemies are angry because of its military advances against terrorist groups,' Ali Akbar Velayati, Supreme Leader Ali Khamenei's top adviser, told Iranian state TV during his visit to eastern Ghouta's bomb-shattered ruins. Advertisement

A joint military operation, possibly with France rather than the U.S. in the lead, could send a message of international unity about enforcing the prohibitions on chemical weapons and counter Syria's political and military support from Russia and Iran.

Macron on Tuesday called for a 'strong and joint response' to the attack in the Syrian town of Douma on Saturday. The Syrian government denies responsibility.

The French president does not need parliamentary permission to launch a military operation. France is already involved in the U.S.-led coalition created in 2014 to fight the Islamic State group in Syria and Iraq. Multiple IS terror attacks have targeted France, including one last month.