Syrian Foreign Minister Walid al-Muallem has denied the Syrian army used chemical weapons in Idlib province, responding to accusations that his country was behind an attack there that left dozens dead and victims foaming at the mouth.
"I stress again that our army has not used chemical weapons and would not use chemical weapons - not against civilians and not against terrorists," he said at a press conference in Damascus on Thursday.
Western powers, including the US, and health organisations have accused the Syrian army of carrying out a chemical attack. A draft resolution was presented to the UN Security Council by the US, France and Britain demanding an investigation.
But the minister said it was not logical for the government to use such weapons at this time.
Mr Al-Muallem expressed reservations about past inquiries in Syria, but would not rule out allowing some sort of international investigation if the body was "neutral".
At least 86 people people including 30 children were killed in Tuesday's suspected chemical attack in Khan Shaykhun in Idlib province, a rebel-held area in north-western Syria, the Syrian Observatory for Human Rights reported.
Mr Al-Muallem's denial comes after Turkey's Justice Minister Bekir Bozdag said that autopsy results conducted on three victims in southern Turkey showed that chemical weapons had been used.
"As a result of the autopsy, it has been established that chemical weapons were used," he said, adding that the autopsies had taken place in the presence of the World Health Organization and the Organization for the Prohibition of Chemical Weapons.
More than two dozen victims of the attack were brought over the border to Turkey for treatment and three died in hospital, broadcaster NTV reported.
Russia, a key backer of al-Assad, claims the Syrian air force targeted a cache of chemical weapons belonging to rebels, though this is sharply disputed by experts.
US President Donald Trump said the attack against civilians was "an affront to humanity by the Assad regime that cannot be tolerated".
US Secretary of State Rex Tillerson called on Russia to re-evaluate its relationship with the Syrian government.
A UN Security Council session on Wednesday failed to take action, amid a stalemate among the permanent members.