Western powers blamed Bashar al-Assad for a suspected chemical attack that killed more than more than 70 people in a rebel-held part of northern Syria as they gathered in Brussels for talks on the conflict.
The long-planned meeting of 70 world powers in the Belgian capital comes ahead of an emergency session on Wednesday of the UN Security Council which will discuss a resolution tabled by the US, UK and France blaming the Assad regime for the attack.
The UN has sought $8bn from the international community to fund humanitarian relief at the conference, at which world powers are discussing long-term plans to rebuild Syria if a political settlement is reached. But the talks were overshadowed by the attack on the town of Khan Sheikhoun in Idlib province.
Antonio Guterres, UN secretary general, said in Brussels that the attack was a “moment of truth” that must be investigated. “The horrific events of yesterday demonstrate that unfortunately war crimes are going on in Syria, that international humanitarian law remains being violated frequently,” he said.
Boris Johnson, the UK foreign secretary, dismissed claims from the Syrian government denials that it was not responsible for the strike. “I’ve seen absolutely nothing to suggest, or rather to lead us to think, that it’s anything but the regime,” Mr Johnson said as he arrived in Brussels.
“All the evidence I have – and there may be more to come out of this – all the evidence I’ve seen suggests that this was the Assad regime who did it in the full knowledge that they were using illegal weapons in a barbaric attack on their own people.”
Sigmar Gabriel, Germany’s foreign minister, said Russia should support the UN resolution. “We find it right that the United Nations Security Council should be occupied with this case of poisonous gas today. We appeal to Russia to support this Security Council resolution, to investigate the incident and to hold to account those responsible,” Mr Gabriel said.
“Of course we should do everything to bring those responsible to an international court because it is one of the most evil war crimes you can imagine.”