South Korea has called for a joint international response to North Korea's suspected use of the banned VX nerve agent in the recent assassination of its leader's half brother during the latest session of the Prohibition of Chemical Weapons, the foreign ministry said Wednesday.

In his key note speech during the OPCW's executive council session in The Hague, Netherlands, on Tuesday, Deputy Minister for Multilateral and Global Affairs Choi Jong-moon underscored North Korea's chemical weapons threats, the Ministry of Foreign Affairs said.

On Feb. 13, two women killed Kim Jong-nam, the estranged half brother of North Korean leader Kim Jong-un, by rubbing the chemical on his face at Kuala Lumpur International Airport.

A subsequent feud between Malaysia and North Korea led to the eviction of the ambassadors from each other's country.

"OPCW member countries and the international community should respond proactively to issues that threaten to shatter the foundation of the Chemical Weapons Convention, including the recent use of the VX nerve agent in Malaysia," Choi was quoted as saying in the speech.

He called on the director-generals of the OPCW and the United Nations to send a joint letter urging North Korea's signing of the CWC, and urged the OPCW to issue a message of warning and condemnation over the use of the chemical weapon, the ministry said.

He also said the issue would need to be referred to the United Nations Security Council for discussion.

The use of the VX at the crowded international airport was serious behavior that could have put many innocent people in danger, Choi also stressed.  

A total of 21 OPCW member countries voiced their support for South Korea's calls, denouncing the North's VX use and calling for the North's signing of the CWC in their own keynote speeches, the ministry added.

The OPCW executive council voiced deep concerns over the use of VX and strongly condemned it, according to the ministry. 

The OPCW is an international organization in charge of implementing the Chemical Weapons Convention, an arms treaty banning the production and use of chemical weapons.

On the sidelines of the conference, Choi also held talks with representatives from the US, Japan, Britain and Malaysia to draw international attention to the North's use of internationally banned chemical, the ministry said. (Yonhap)