SYRIA'S president Bashar al-Assad has said reports of a chemical attack by his forces are "100 per cent fabrication".
He insisted that his military was not responsible and claimed it was a "fabrication" to justify the US missile strike.
In an interview with the news agency AFP, he said: "There was no order to make any attack.
"We don't have any chemical weapons, we gave up our arsenal a few years ago.
"Even if we have them, we wouldn't use them. We have never used our chemical arsenal in our history."
He claimed the US and the west were "hand in glove with the terrorists".
"They fabricated the whole story in order to have a pretext for the attack," he said.
More than 80 people were killed in the rebel-held town of Khan Sheikhoun last week and hundreds suffered symptoms consistent with a nerve agent.
Witnesses said they saw warplanes attack the town, but Russia – one of Syria's few international allies – says a rebel depot of chemical munitions was hit.
Shocking footage showed victims, many of them children, convulsing and foaming at the mouth. Sufferers were taken to hospitals across the border in Turkey.
World leaders have called for an international probe into the attack, which prompted a retaliatory US missile strike on a Syrian airbase.
But Russia vetoed a draft UN security council resolution which would require the regime to provide detailed information about air operations and immediate access to air bases.
British prime minister Theresa May said Russia is on the "wrong side of this argument" by failing to condemn the deadly chemical attack.
She said it was "highly likely" the attack had been carried out by the Syrian regime.
"Russia is on the wrong side of this argument but we are willing to work with Russia to bring an end to the conflict in Syria, to bring about a political solution in Syria, but that political solution has to be without Assad," she said.
British scientists have said a toxic gas known as sarin was used in the attack, Mrs May added.
"They are very clear that sarin or a sarin-like substance was used and as our ambassador to the United Nations made clear yesterday, like the United States, we believe it is highly likely that attack was carried out by the Assad regime."
Meanwhile, the Pentagon has said US military has dropped the biggest non-nuclear bomb ever used in combat on an Islamic State group tunnel complex in Afghanistan.
The GBU-43/B Massive Ordnance Air Blast Bomb (MOAB), dubbed "the mother of all bombs", was first tested in 2003 but had not been used before.
The Pentagon said it was dropped from a US aircraft in Nangarhar province.
The development emerged just hours after the Pentagon admitted an air strike in Syria mistakenly killed 18 rebels.
