Kim Jong Nam was murdered on February 13 at Kuala Lumpur International Airport, where he was assaulted by two women who allegedly smeared his face with VX, a chemical classified by the United Nations as a weapon of mass destruction.
"The Ministry strongly condemns the use of such a chemical weapon by anyone, anywhere and under any circumstances. Its use at a public place could have endangered the general public," it said in a statement.
The foreign ministry said it was in close contact with the Organisation for the Prohibition of Chemical Weapons, an inter-governmental organisation based in the Netherlands, regarding the incident.
"Malaysia does not produce, stockpile, import, export or use any Schedule 1 toxic chemicals including VX, and has made annual declarations to that effect to the OPCW," the statement said.
Relations between Malaysia and North Korea, who have maintained friendly ties for decades, have soured since the killing of Kim Jong Nam at the airport two weeks ago.
North Korea's envoy to Malaysia has said earlier that police investigations in the case cannot be trusted. North Korea has not accepted that the dead man is Kim Jong Nam, and said on Thursday that their citizen may have died of a heart attack.
South Korean intelligence and US officials say the murder was an assassination organised by North Korean agents, though the only suspects charged in the case so far are an Indonesian woman and a Vietnamese woman.
A North Korean suspect held over the killing was released from a detention centre on Friday, and driven away in a police convoy, a Reuters witness said.
Ri Jong Chol, who had been detained a few days after the killing was taken to the immigration office to prepare his deportation to North Korea.
Malaysia's attorney-general told Reuters on Thursday that he would be released due to insufficient evidence.
Police have identified seven other North Koreans wanted in connection with the killing, including a senior embassy official in Kuala Lumpur.
(Reporting by Praveen Menon and Angie Teo; writing by Jack Kim and Praveen Menon; Editing by Simon Cameron-Moore)