Bahrain’s Sheikh Khaled bin Ahmed al-Khalifa was speaking at the start of a meeting of foreign ministers from the six GCC countries.

Gulf Arab states renewed their demands on Tuesday for the United Nations Security Council to take deterrent measures against Syrian President Bashar al-Assad’s government over a chemical weapons attack that killed hundreds of people.

The statement was the first from the Sunni Muslim-led Gulf Cooperation Council, a main backer of rebels fighting to overthrow Assad, a member of the Alawite sect of Shi’ite Islam, since Russia unveiled a proposal to avoid military strikes by dismantling Syria’s chemical weapons.

“The GCC condemns the ugly crime committed by the Syrian regime by using internationally banned chemical weapons, which resulted in the killing of hundreds of civilians,” said Bahrain’s Foreign Minister Sheikh Khaled bin Ahmed al-Khalifa.

He was speaking at the start of a meeting of foreign ministers from the six countries, which also include Saudi Arabia, Kuwait, Qatar, the United Arab Emirates and Oman.

“This requires the United Nations and the international community, represented by the security council, to shoulder its responsibility,” he added.

He called for “appropriate deterrent measures against those who committed this crime”.

The United States has accused Assad of responsibility for last month’s attack on Damascus suburbs. He denies any links.

The Russian proposal, which Syria accepted, offers U.S. President Barack Obama a way out of ordering strikes, days before votes in Congress seeking authorisation to use force.