The United States has circulated a draft Security Council resolution that aims to establish an accountability mechanism for chemical weapons attacks in Syria — a subject that has vexed the Council for months, amid repeated accusations that the Syrian government is using chlorine as a weapon.

Council diplomats confirmed the circulation of the draft, which was obtained by VICE News, late Thursday afternoon.

The resolution, which diplomats said will be negotiated starting next week, requests that UN Secretary General Ban Ki-moon and Ahmet Üzümcü, director-general of the Organization for the Prohibition of Chemical Weapons (OPCW), submit recommendations on the mechanism no later than 15 days following its potential adoption at the Council.

The joint OPCW-UN mechanism, which has been discussed privately for several months, would "identify to the greatest extent feasible individuals, entities, groups, or governments who were perpetrators, organizers, sponsors, or otherwise involved in use of chemical weapons in Syria."

If sanctioned by the Council, the joint body would investigate incidents in Syria that the OPCW has determined "involved or likely involved the use of chemical weapons."

Last fall, the OPCW determined that chlorine had been used "systematically and repeatedly" as a weapon in Syria. In early March, the council condemned it, and threatened additional action under Chapter VII of the UN's Charter against those who deploy it. The OPCW, however, is not mandated to determine culpability, and further steps to do so have since languished at the Council.

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"Given the frequent allegations of chlorine attacks in Syria, and the absence of any international body to identify the perpetrators of chemical weapons attacks, it is critical that the UN Security Council find consensus and set up an independent investigative mechanism," US ambassador to the UN Samantha Power said in a statement.

The text's approval is hardly guaranteed, as it's likely to face intense scrutiny from Russia, the strongest ally of Syrian president Bashar al-Assad on the Council.

Following a deadly 2013 chemical weapons attack in the suburbs of Damascus, the Syrian government reached a deal to destroy its stockpiles. Chlorine, however, is a so-called "dual use" chemical and is not considered illegal unless deployed as a weapon.

Western governments and human rights organizations have repeatedly accused Assad's military of rigging chlorine to barrel bombs before dropping them into rebel-controlled areas. The Syrian American Medical Society, which helps run field hospitals in the country, said last month that it had documented 31 chlorine attacks between March 16 and June 9.

The Syrian government denies it has ever used chemical weapons in Syria, including chlorine.