The regime of Syrian President Bashar al-Assad was responsible for a deadly sarin gas attack on a rebel-held town in April, a UN report found on Thursday.

"The panel is confident that the Syrian Arab Republic is responsible for the release of sarin at Khan Sheikhun on 4 April 2017," stated the report seen by AFP.

More than 87 people died in the nerve gas attack on the town in Syria's northwestern Idlib province.

Horrific images from the immediate aftermath of the attack drew global outrage and prompted the United States to fire cruise missiles at a Syrian air base from which the West says the assault was launched.

Last month, UN war crimes investigators said they had evidence that the Syrian air force was behind the attack, despite repeated denials from Damascus.

This is the same chemical weapons watchdog being disbanded bc/ of Russia’s veto Tuesday at UNSC. Crazily, this means that, henceforth, no organiz will exist to identify the perpetrator of any future CW attack. #impunity https://t.co/ADvEHIj8FW — Samantha Power (@SamanthaJPower) October 26, 2017

Syria ally Russia maintains that the sarin attack was most likely caused by a bomb set off directly on the ground, not by a Syrian air strike as alleged by the West.