UNITED NATIONS (Reuters) - Russia said on Monday it was talking to the United States about the U.N. Security Council renewing an international inquiry into chemical weapons attacks in Syria, but Washington countered that Moscow had refused to engage on a U.S.-drafted resolution. The mandate for the joint inquiry by the U.N. and the Organization for the Prohibition of Chemical Weapons (OPCW), which has found the Syrian government used the banned nerve agent sarin in an April 4 attack, expires on Friday. Russia vetoed an initial U.S. bid to renew the joint  investigation on Oct. 24, saying it wanted to wait for the release of the latest investigation s report two days later. It has since proposed its own rival draft resolution.  We are talking to the U.S., it s not over yet,  Russian U.N. Ambassador Vassily Nebenzia told reporters on Monday.  The inquiry s report found the Syrian government was responsible for the April 4 attack using sarin in the opposition-held town of Khan Sheikhoun, killing dozens of people. The Syrian government has denied using chemical weapons.  Russia has refused to engage on our draft resolution   which the vast majority of council members agree is the most viable text   in spite of our multiple attempts to consider Russian concerns,  a spokesman for the U.S. mission to the United Nations said on Monday.   A resolution needs nine votes in favor and no vetoes by Russia, China, the United States, Britain and France to pass. The council unanimously created the inquiry, known as the Joint Investigative Mechanism (JIM), in 2015 and renewed it in 2016.  It is important that the JIM is renewed but on an updated mandate because the systemic errors that we saw with the recent report should be corrected and that s the aim of our resolution,  Nebenzia said.  He added that if the mandate of the inquiry was not renewed,  It may send a bad signal, but the way the investigation has been conducted sends an even worse signal.  The JIM previously found that Syrian government forces were responsible for three chlorine gas attacks in 2014 and 2015 and that Islamic State militants used mustard gas.   The draft text Russia put forward without any negotiation is unhelpful, has no support, and cannot be taken seriously,  said the spokesman for the U.S. mission.  Syria agreed to destroy its chemical weapons in 2013 under a deal brokered by Russia and the United States. 