North Korea’s chemical and biological weapons are in the spotlight, as Pyongyang has been accused of using VX nerve agent to kill Kim Jong-nam, the half-brother of its leader Kim Jong-un, at an airport in Malaysia.

South Korea and the US have focused on North Korea’s nuclear and missile threats, but the assassination has aroused their attention to its chemical and biological weapons. Using VX to assassinate Kim Jong-nam indicates the communist state’s chemical warfare capability.

VX is an extremely toxic material. The tasteless and odorless substance severely disrupts the body’s nervous system and its only use is in chemical warfare. Just 10 milligrams is sufficient to be fatal through skin contact, and the lethal dose for inhalation is estimated to be 30-50 milligrams per cubic meter of air.

The production and stockpiling of VX exceeding 100 grams per year was outlawed by the Chemical Weapons Convention of 1993. But North Korea has not signed or acceded to the convention.

VX is far more potent than sarin, another nerve agent used in the 1996 attack on the Tokyo subway. Iraq was found to have used chemical agents against the Kurds in 1988. UN laboratories detected traces of VX on Iraqi warhead remnants.

If war breaks out on the Korean Peninsula, North Korea could disperse lethal chemicals over South Korean troops and civilians. It may use them to kill specific persons in South Korea or sell them to international terrorist groups.

The South Korean Defense Ministry said in its 2014 Defense White Paper that the North began producing chemical weapons in the 1980s and that it has about 2,500 to 5,000 tons of chemical weapons, including VX, mustard gas and sarin.

Pentagon spokesman Jeff Davis recently said VX is not particularly difficult to make and that it can be attached to a warhead and other weapons -- from a mortar or artillery shell to a missile.

Such weapons can also be delivered by airplanes.

The communist state is estimated to have a stockpile of artillery shells and missile warheads with chemical and biological agents.

In 2015, Melissa Hanham of the James Marline Center for Nonproliferation Studies released an analysis of photos of Kim Jong-un visiting a factory supposedly for the production of pesticides. Hanham’s analysis concluded the factory actually produces weaponized anthrax.

The Korea Institute for Defense Analyses last year estimated that North Korea possesses 25 kinds of chemical agents and 13 pathogens for biological weapons, such as anthrax and bubonic plague. Though the North signed the Biological Weapons Convention in 1987, it has failed to provide a BWC confidence-building measure since 1990.

South Korea and the US have held joint exercises, called the Able Response, every year since 2011 to respond to biological warfare threats in the Korean Peninsula.

The South Korean military says it has fielded chemical and biological decontamination vehicles and detectors, including reconnaissance robots.

In 2013, South Korea and the US agreed to build a joint surveillance system to detect biochemical agents along the DMZ and to share information.

In 2014, South Korea became the fourth country after Canada, the US and Britain to produce area detection devices to check for dangerous chemicals at key facilities.

Despite such preparations, the military says it needs to further beef up its chemical and biological warfare capability against the North.

Pyongyang’s biochemical warfare threats have drawn less attention than its nuclear and missile tests. Using VX to kill Kim Jong-nam highlights the need to review the country’s preparedness against such threats.

The government should also make diplomatic efforts to alert the international community to the mass destructive power of chemical and biological weapons in the hands of an unpredictable dictator in the North.

The UN needs to respond to the communist state’s biochemical weapons as strongly as it does to its nuclear and missile programs.