President Donald Trump on Thursday voiced his support for the renewal of a United Nations investigation into chemical attacks in Syria, a proposal the Security Council is set to vote on later in the day.
Rycroft said the majority of the Security Council's 15 member states supported the US resolution and he wasn't aware of any substantial meetings between Russian Federation and the U.S.to reach a compromise.
It means that the JIM's mandate expires at midnight Thursday, rather than be extended for another year.
Russian Federation cast its 10th veto on Thursday of United Nations Security Council action on Syria since the war began in 2011, blocking a US-drafted resolution to renew an worldwide inquiry into who is to blame for chemical weapons attacks in Syria.
Russian Federation and Iran back President Bashar al-Assad in the conflict, while Turkey and the United States support differing rebel groups fighting the government.
The White House in June cautioned against another possible chemical weapons strike in Syria, warning that the Assad government would "pay a heavy price" for it.
Addressing the council, US Ambassador Nikki Haley assailed the veto as a "deep blow", saying "Russia has killed the investigative mechanism which has overwhelming support of this council". She accused Moscow of "killing" the resolution, which had received backing from most members of the UN Security Council, and of "undermining" the UN's ability to prevent chemical attacks in the future. After the council voted on the U.S. draft, Bolivia then requested that the body vote on the Russian text.
Haley tweeted after the vote that "by using the veto to kill a mechanism in Syria that holds users of chemical weapons accountable, Russian Federation proves they can not be trusted or credible as we work towards a political solution in Syria".
French Ambassador Francois Delattre urged council members to "please think twice before throwing it away, because this would be a major setback for the fundamentals of our common security".
Nebenzia said Monday, "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".
While Russia agreed to the 2015 creation of the inquiry, known as the Joint Investigative Mechanism (JIM), it has consistently questioned its findings, which also concluded that the Syrian government used chlorine as a weapon several times.