The United States is pushing for a quick vote by the United Nations Security Council on extending the authority of an inspection team charged with determining who is responsible for chemical-weapons attacks in Syria, putting itself at odds with Russia.

U.S. Ambassador to the UN Nikki Haley said on October 18 that she was circulating a resolution that would extend by another year the work of the Joint Investigative Mechanism (JIM), and she called for a vote on the extension before a scheduled October 26 report by the group on who is responsible for an April 4 sarin-gas attack on Khan Sheikhun that killed nearly 90 people.

Haley said that "there's overwhelming support" on the council for her proposed extension of the JIM's inspection mandate, which expires in mid-November, but she expects Russia to object to any rushed vote.

Russian Ambassador Mikhail Ulyanov, who heads the country's delegation to the UN General Assembly's disarmament committee, said last week that Russia wanted to wait to see the report on the Khan Sheikhun attack before deciding whether to extend the inspectors' mandate.

"Russia has made it very clear that should the report blame Syria" for the attack, Moscow will vote against renewing the JIM's authority, Haley said.

"We can't work like that. We need to look at the attack. We need to prove that it was actually a chemical, and then we need to look at who did it. We can't go and pick and choose who we want to be at fault, who we don't."

The United States and its Western allies on the council have maintained that the April attack was launched by a Syrian government aircraft that took off from the Shayrat airfield in Syria.

Based on intelligence that came to that conclusion, U.S. President Donald Trump ordered retaliatory missile strikes on the airfield shortly after the attack occurred.

But Russia and its ally Syria blame Syrian rebel groups for the attack. Ulyanov last week accused the JIM team of failing to sample for sarin at the Shayrat airfield, a move he said was "scandalous" and likely would result in a "biased" report on the incident.

Russia could decide to use its veto power on the Security Council to block renewal of JIM's authority, effectively shutting down dozens of investigations of deadly gas attacks in Syria.

"It would be a shame if Russia chose to decide whether to have an investigative mechanism based on who is to blame in Khan Sheikhun," Haley said.

A fact-finding mission by the Organization for the Prohibition of Chemical Weapons reported on June 30 that sarin nerve gas was used in the Khan Sheikhun attack, but it is up to the JIM inspection team to determine who is responsible.

The UN has said that its inspectors are looking at more than 60 alleged incidents of chemical-weapons use in Syria between December 2015 and the end of March 2016.

"Given the multiple chemical attacks that we have seen in Syria, renewing the mandate for the Joint Investigative Mechanism...is critical," Haley said.

"We need to ensure accountability for these attacks, which have killed hundreds of innocent civilians, including children who were sleeping or trying to go to school," she said.

UN Secretary-General Antonio Guterres on October 18 agreed that the JIM's investigative authority should be renewed, calling it a "very important tool" that he "fully supports."

The JIM has already determined that Syrian government forces were responsible for chlorine-gas attacks on three villages in 2014 and 2015. It also determined that Islamic State extremists used mustard gas in 2015.

With reporting by AP and AFP