Experts from the U.N. and a chemical weapons watchdog are blaming Syria's government for a sarin nerve gas attack that killed over 90 people last April.

Their report, obtained Thursday by The Associated Press, says leaders of the expert body are "confident that the Syrian Arab Republic is responsible for the release of sarin at Khan Sheikhoun on April 4, 2017."

The report supports the initial findings by the United States, France and Britain that a Syrian military plane dropped a bomb with sarin on the town.

Russia on Friday criticized the United Nations report, with a deputy foreign minister saying it contained inconsistencies and unverified evidence.

"Even the first cursory read shows … many inconsistencies, logical discrepancies, using doubtful witness accounts and unverified evidence … all of this is still [in the report]," Deputy Foreign Minister Sergei Ryabkov told Interfax news agency. Ryabkov said other nations were seeking to use the report to "resolve their own strategic geopolitical issues in Syria." Russia would analyze the findings and publish a response soon, he added.

Syria and Russia, close allies, have denied any attack and have strongly criticized the Joint Investigative Mechanism (JIM), which was established by the U.N. and the Organization for the Prohibition of Chemical Weapons to determine responsibility for chemical weapons attacks in Syria.

The attack in Khan Sheikhoun sparked outrage around the world as photos and video of the aftermath, including quivering children dying on camera, were widely broadcast.

The United States blamed the Syrian military and launched a punitive strike days later on the Shayrat Air Base, from where it said the attack was launched.

Responding to the report, U.S. ambassador to the U.N. Nikki Haley said: "Today's report confirms what we have long known to be true. Time and again, we see independent confirmation of chemical weapons use by the Assad regime."

Clearly referring to Russia, she said: "In spite of these independent reports, we still see some countries trying to protect the regime. That must end now."

The U.N. Security Council should make it clear that "the use of chemical weapons by anyone will not be tolerated," Haley said.

A fact-finding mission by the Organization for the Prohibition of Chemical Weapons reported on June 30 that sarin was used in the Khan Sheikhoun attack and "sulfur mustard" in Um Hosh. But JIM experts had the task of determining who conducted the attacks.

The JIM experts said Thursday they are confident the Daesh extremist group was responsible for an attack in Um Hosh in Aleppo on Sept. 15-16, 2016, that used "sulfur mustard," the chemical weapon commonly known as mustard gas.

The report was issued two days after Russia vetoed a U.S.-sponsored resolution to extend the mandate of JIM investigators another year after it expires on Nov. 17.

U.N. Secretary-General Antonio Guterres reiterated "his full confidence in the professionalism, impartiality and objectivity" of the JIM and looks forward to the U.N. Security Council's consideration of the report on Nov. 7, U.N. deputy spokesman Farhan Haq said.