They were charged under Section 302 of the Penal Code, which provides for the mandatory death sentence upon conviction.
It was reported that Jong-nam was at klia2 on Feb 13 to board a flight to Macau when two women approached and suddenly wiped his face with toxic liquid which was later identified as the VX nerve agent.
The VX nerve agent used on Kim is classified as a weapon of mass destruction by the United Nations.
The pair have claimed from the start that they did not know they were taking part in the global assassination of dictator Kim Jong-un's estranged relative, and believed they were taking part in a TV prank show.
Defence lawyers are convinced the real culprits have left Malaysia and that the women's innocence will be proven in court.
"We are fairly confident that at the end of trial, they will probably be acquitted", Hisyam Teh Poh Teik, a lawyer for Huong, told AFP.
Trial begins for women accused of assassinating Kim Jong-un's brother
The diminutive pair bowed their heads as they were led into court past waiting journalists.
There are still many unanswered questions surrounding the murder.
On March 1, the duo was charged at the Sepang magistrate's court - along with four others who are still at large - with murdering 45-year-old "Kim Chol".
Some North Korean figures suspected of links to the plot fled Malaysia immediately after the assassination, while others were allowed to leave the country later to ease the diplomatic crisis.
The trial will be heard at the High Court for 23 days and the prosecution is expected to call 30 to 40 witnesses, including 10 experts, to testify. The defence is then likely to be called.
An Asian Cup football qualifier between Malaysia and North Korea was postponed amid the crisis, and delayed this week for a third time after Kuala Lumpur imposed a ban on travel to North Korea due to surging nuclear tensions.
Bolton toddler bridge plunge man released
A man has been arrested after dropping a three-year-old from a bridge into a river in an apparent murder-suicide attempt. Police also pulled the man to safety after he plunged in after her and he was arrested on suspicion of attempted murder .
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