Two women accused of murdering the half-brother of North Korean leader Kim Jong Un have pleaded not guilty in a Malaysian court.

Indonesian Siti Aisyah and Vietnamese Doan Thi Huong are suspected of smearing Kim Jong Nam's face with banned VX nerve agent on February 13th at an airport terminal in Kuala Lumpur.

Kim Jong Nam, who was aged in his mid-40s, had been waiting to board a plane to Macau when he was poisoned. He died about 20 minutes later.

The women entered their pleas through interpreters at Shah Alam High Court on the first day of the trial, which is expected to last for about two months.

Aisyah (25) appeared in court wearing traditional Malay dress while Huong (29) was in a blue top.

Both claim they were tricked into believing they were taking part in a prank for a hidden camera TV show but they could face the death penalty if found guilty of murder.

Among the first witnesses for the prosecution will be medical experts who will talk about the cause of Kim's death.

After the prosecution has called its witnesses, the judge will decide if the case is strong enough for the women to have to mount their defence.

This composite photo shows Kim Jong Nam (left) in Japan in 2001, and North Korean leader Kim Jong Un (right) in Pyongyang | Image: Shizuo Kambayashi, Wong Maye-E AP/Press Association Images

Aisyah and Huong are the only suspects arrested in what South Korean intelligence says was part of a five-year plot by the North Korean leader to kill a half-brother he reportedly never met.

Several North Koreans suspected of involvement left the country in the hours after the attack.

Others left later as part of a diplomatic deal with Pyongyang, although North Korea has denied any role in the killing - saying the victim died of a heart attack and refusing to even say he was Kim Jong Nam.

The judge has been asked to consider identifying four of these other people described on the charge sheet as also having an intention to kill Mr Kim.

Reporter Katie Stallard said the case "has strained relations" between North Korea and Malaysia, with North Korea accusing Malaysia of taking part in a "conspiratorial racket" with South Korea, and Malaysia expelling North Korea's ambassador.

Stallard added: "North Korea also briefly prevented Malaysian citizens from leaving the country after the attack, until Kim Jong Nam's body was returned to them, and three North Korean men wanted for questioning were allowed to return to Pyongyang.

"Last week Malaysia barred its citizens from travelling to North Korea, and said it would cut off business links, in line with the latest UN sanctions."

Mr Kim was the eldest son of the ruling North Korean dynasty but he reportedly got on the wrong side of the regime when he tried to enter Japan on a false passport in 2001.

He had been living outside North Korea for many years at the time of his death.