The U.S. and Western powers have clashed with Russia and others at the global chemical weapons watchdog over a new investigative team being set up to apportion blame for poison gas and nerve agent attacks.

The United States and Britain went head-to-head with Russia, China over the boosted powers that members agreed to give the Organization for the Prohibition of Chemical Weapons in June.

At a tense meeting in The Hague, Russia said the new team would wield unlawful powers within the Organization for the Prohibition of Chemical Weapons and on Monday called for an "expert group" to assess the viability of such a team, something the U.S. insisted would hamstring the development of the team. The U.K. ambassador to the OPCW said that the Russian move would "undermine" plans to set up the team.

The West pushed through the new powers after a string of chemical attacks in Syria, as well as a nerve agent attack on Russian former double agent Sergei Skripal in the British city of Salisbury in March. Britain accused Russia of carrying out the attack using a Soviet-era chemical called Novichok and the West has since imposed a series of sanctions on Moscow. Moscow denies any involvement.

British envoy to the OPCW Peter Wilson called any attempt to limit the watchdog's power to attribute blame for chemical attacks "unacceptable."

But Russia's envoy Alexander Shulgin hit back, saying that Western claims of chemical weapons use by Damascus and Moscow were a "scam" and "out and out lies." He added that Russia had a "principled position regarding the illegitimacy" of the new investigative powers, adding that they "infringe on the properties of the U.N. Security Council," where Russia has a veto.

The meeting is also the first since the expulsion of four Russians accused by Dutch authorities in October of trying to hack into the OPCW's computer system, using electronic equipment hidden in a car parked outside a nearby hotel.

The OPCW said the two-week meeting of the 193 member countries is meant to "discuss the future of the organization." New OPCW director-general Fernando Arias warned in his opening address yesterday that the "international norm against the use of chemical weapons has come under strain." "Their repeated use poses a challenge that must be met with strong and unified resolve," he added.

Winner of the Nobel Peace Prize in 2013, the OPCW is responsible for upholding the 1997 Chemical Weapons Convention to end the use of all toxic arms. So far it says it has overseen the destruction of 96.5 percent of the world's chemical arms stocks. But in recent years it has seen its role expand to cover the investigation of a wave of chemicals attacks in the Syrian civil war, as well as the Salisbury attack and the 2017 killing in Malaysia of a half-brother of North Korean leader Kim Jong Un.