Nine Malaysians - three embassy staff and members of their families - are in North Korea while about 315 North Koreans are in Malaysia.
Subsequently, Kuala Lumpur made a decision to expel the North Korean ambassador.
Malaysian police said that eight North Koreans are suspected of being involved in the killing, along with the two women.
But the Malaysian government is reluctant to let Hyon and Kim leave after it already had to release and deport Ri Jong-chol, the only North Korean suspect in the hit who had been arrested, due to a lack of evidence.
It said that a North Korean citizen carrying a diplomatic passport fell into a state of "shock", without making any references to his identity.
Malaysia retaliated by banning some 1,000 North Korean, mostly illegal workers earning hard currency for their regime, from leaving until the safety of the Malaysians in the North is assured.
Kim Jong-nam, who was the elder half-brother of Kim Jong-un, had been passed over for the North Korean succession and was living in the Chinese territory of Macau at the time of his death.