Autopsy results have revealed that chemical weapons were used in an attack which killed at least 70 people in Syria's Idlib province, Turkish Justice Minister Bekir Bozdag told reporters on Thursday.

Thirty-two victims of Tuesday's attack have been brought to Turkey and three have subsequently died.

U.S. President Donald Trump accused Syrian President Bashar al-Assad's government of going "beyond a red line" with the poison gas attack on civilians and said his attitude toward Syria and Assad had changed.