N. Korean ambassador to Malaysia.

North Korea said Monday it would expel Malaysia’s ambassador after its own envoy was ordered out of the Southeast Asian nation, in an increasingly bitter row over the assassination of Kim Jong-Nam at Kuala Lumpur International Airport.

“The Foreign Ministry of the DPRK (North Korea) notifies that the Malaysian ambassador to the DPRK is labeled as a persona non grata… and demanded that the ambassador leave the DPRK,” state news agency KCNA said, giving a 48-hour deadline.

The KCNA report came shortly after the North’s ambassador Kang Chol flew home from Kuala Lumpur. Malaysia’s ambassador to Pyongyang had already been recalled for consultations as the two countries traded barbs over an investigation into the killing of the North Korean leader’s half-brother with VX nerve agent last month.

In Kuala Lumpur, Malaysia’s foreign ministry confirmed its ambassador to Pyongyang had been officially declared persona non grata.

“This reciprocal action is normal in diplomacy,” said ministry director-general Raja Nurshirwan. North Korea has not acknowledged the dead man’s identity but has repeatedly attacked the murder investigation and demanded a second autopsy, accusing Malaysia of conniving with its enemies.

Airport CCTV footage shows two women approaching the 45-year-old victim and apparently smearing his face with a cloth. Police say he suffered a seizure and died less than 20 minutes later. Swabs of his face revealed traces of the VX nerve agent.

Two women – one Vietnamese and one Indonesian – are in custody and have been charged with the murder while police are seeking seven North Korean suspects, four of whom left Malaysia on February 13, the day of the assassination.

Police last week released the only North Korean they had arrested, citing a lack of evidence.

South Korea has blamed Pyongyang for the murder, citing what it says was a standing order from leader Kim Jong-Un to kill his exiled half-brother.