Bashar-al Assad, the Syrian President, has insisted that the reports of a chemical attack by his country's forces on its own people were a "100 per cent fabrication".

In an interview with Agence France-Presse[AFP], he said: "There was no order to make any attack".

Western countries, including the US and UK, have claimed there is incontrovertible proof that Assad's forces were behind the attack; Donald Trump, the US President, has branded the Syrian leader an "animal" and a "truly evil person".

However, Russia has argued there is simply no proof of an attack ordered by Assad and suggested it was carried out by rebel forces, seeking to draw America into the conflict. Vladimir Putin has likened Washington and London's allegations of a chemical weapons attack to those now-discredited claims that Saddam Hussein had weapons of mass destruction.

This week, Russia blocked a draft resolution backed by America, Britain and France to denounce the attack in the rebel-held town of Khan Sheikhoun and to tell Assad's regime to provide access for investigators and information such as flight plans.

Last week, more than 80 people were killed and hundreds suffered symptoms consistent with a nerve agent. Tests have since suggested lethal sarin gas was used.

Mr Assad told AFP that his government had given up its arsenal of chemical weapons four years ago. He stressed: "Even if we have them, we wouldn't use them."

He accused the West of making up the claim to enable it to carry out the retaliatory air strikes on a Syrian government airbase.

"It's stage one - the play we saw on social network and TVs - then propaganda and then stage two - the military attack," said Assad.

Speaking from his office in Damascus, he claimed Washington was "not serious" about ending the conflict, saying: "They want to use it as an umbrella for the terrorists."

The Syrian President made clear he would only allow an "impartial" investigation into the strike at Khan Sheikhoun to make sure it was not used for "politicised purposes".