Malaysia has charged two women - an Indonesian and a Vietnamese - with murdering the estranged half brother of North Korea's leader in an assassination using a super-toxic nerve agent that killed in minutes.

Siti Aishah, a 25-year-old mother of one from Jakarta, and Doan Thi Huong, 28, from rural northern Vietnam, could be hanged if they are convicted for the killing of Kim Jong Nam at Kuala Lumpur International Airport on February 13.

Police brought the two women to court handcuffed. As they left, they were made to wear bullet-proof vests, reflecting Malaysian authorities' fears that others involved in the killing could want the women silenced.

No plea was recorded after the charges were read out against them.

But, Aishah and Huong have told diplomats who visited them in custody that they were unwitting pawns in an assassination that US officials and South Korean intelligence have said was organised by North Korean agents.

Huong's lawyer told reporters outside the court that his client had told him she was innocent.

"She denied. She denied. She said 'I'm innocent'," Selvam Shanmugam said.

"Of course, she's definitely distressed because she is facing death penalty," he added.

The next court date will be on April 13, when prosecutors will apply for the accused to be tried jointly.

Kim, who had criticised the regime of his family and his half-brother Kim Jong Un, died after the two women allegedly smeared VX nerve agent, a chemical described by the United Nations as a weapon of mass destruction, across his face.

He had been preparing to catch a flight to Macau, the Chinese territory where he had been living under Beijing's protection since going into exile several years ago.

According to the charges the women and four unnamed people, who are still at large, were in the airport departure, with the intention to murder Kim.

One North Korean man, identified by police as Ri Jong Chol, is still in police custody and has not been charged yet. Police have identified seven other North Koreans wanted in connection with the case, including an embassy official in Kuala Lumpur.

Amid a bitter diplomatic row, members of Malaysia's cabinet met with a high level North Korean delegation that arrived on Tuesday to press for the release of the citizen in custody, and for the body to be handed over.

Health Minister Subramaniam Sathasivam told reporters he was not at that meeting, but a decision would eventually be made on what to do with the body as no next of kin had come forward for formal identification.

Doan Thi Huong (left) and Siti Aishah. (AAP)