DAMASCUS – The Syrian foreign minister has set out conditions for any UN investigation into the deaths of dozens of people from a chemical agent on Tuesday.
Walid Muallem told the BBC it would have to be non-political, involve “many countries” and “start from Damascus” before his government could accept.
He denied Syria had dropped chemical weapons from the air, despite facing widespread scepticism.
The UN children’s fund has confirmed that at least 27 children were killed.
Russia, one of Syrian President Bashar al-Assad’s few allies, was challenged by the US and UK at the UN Security Council on Wednesday when it sought to argue the mass poisoning had been caused by the rebels’ own chemical weapons.
Washington has hinted it might change its policy towards Syria in response to the deaths.
Warplanes attacked Khan Sheikhoun, about 50km (30 miles) south of the city of Idlib, early on Tuesday, when many people were asleep, witnesses and activists say.
The opposition-run health directorate in Idlib province says at least 84 people, including 27 children and 19 women, were killed. Another 546 people were injured, many of whom remain in a serious condition.
Evidence has mounted that the victims were killed with a nerve agent such as Sarin.
Medical charity Medecins Sans Frontieres (MSF) said its staff had treated eight patients brought to a hospital on the Turkish border whose symptoms were consistent with such exposure.
Turkish Foreign Minister Bekir Bozdag said on Thursday that autopsies had confirmed that chemical weapons were used.
Foreign Minister Muallem told BBC Arabic that the Syrian government would, together with Russia, consider accepting an investigation mandated by the UN Security Council, if its conditions were met.
Speaking separately at a news conference, he accused jihadist groups not party to a ceasefire brokered by Russia and Turkey of storing “chemical weapons in urban and residential areas”.
The Russian military confirmed on Wednesday that the Syrian air force had launched air strikes in the Khan Sheikhoun area but said they had hit a rebel depot full of chemical munitions.
Hamish de Bretton-Gordon, a former commanding officer of the British Armed Forces Joint Chemical Biological Radiological Nuclear Regiment, told the BBC it was “pretty fanciful”.
“Axiomatically, if you blow up Sarin, you destroy it,” he said.
“It’s very clear it’s a Sarin attack. The view that it’s an al-Qaeda or rebel stockpile of Sarin that’s been blown up in an explosion, I think is completely unsustainable and completely untrue.”
Hasan Haj Ali, commander of the Free Idlib Army rebel group, told Reuters news agency: “Everyone saw the plane while it was bombing with gas.”
Mr Trump said on Wednesday: “My attitude towards Syria and Assad has changed very much… You’re now talking about a whole different level.”
However, he gave no details.
On Thursday Secretary of State Rex Tillerson said Mr Assad’s future was uncertain: “It would seem there is no role for him to govern the Syrian people”.
He added that the US was still considering its response.
The statements came only days after the US ambassador to the UN, Nikki Haley, said the US no longer prioritised the removal of President Assad – a shift in US policy from the Obama era.
Mr Trump has been promising a new strategy for Syria and Iraq and there have been some increases in troop numbers but this latest development will increase the pressure for more decisive action, the BBC’s Gary O’Donoghue reports from Washington.