Police officers guarded the entrance of the forensic department of Kuala Lumpur General Hospital, where Kim Jong Nam's body was, in Kuala Lumpur, Malaysia, Feb. 15, 2017. North Korean leader Kim Jong Un's older half brother Kim Jong Nam was killed in Malaysia. Getty Images

Malaysia has canceled visa-free travel for North Koreans, Deputy Prime Minister Ahmad Zahid Hamidi said Thursday at a press conference after the ministry's Excellent Service Award ceremony in Malaysia. The move comes amid strained ties between the two countries following the murder of Kim Jong Nam, the estranged half brother of North Korean leader Kim Jong Un.

"I hope the decision of the Home Ministry will be implemented by the Immigration Department for the sake of national security," said Ahmad Zahid, who is also the home minister, the Bernama state news agency reported. All North Koreans would have to apply for visa to enter Malaysia and the rules concerning this will be effective from March 6, he added.

Kim Jong Nam was killed Feb. 13 at the Kuala Lumpur airport after being poisoned by a toxic nerve agent.

Malaysia's attorney general said Thursday that a North Korean man named Ri Jong Chol, who was arrested following the incident, will be released and deported Friday because they found no evidence against him, the Associated Press reported.

On Wednesday, two women, Siti Aisyah, 25, from Jakarta, Indonesia, and Doan Thi Huong, 28, from the rural northern Vietnam, were charged with Kim Jong Nam's murder and were accused of applying the VX nerve agent on his face while he was about to fly out of the Kuala Lumpur airport, the Guardian reported.

The murder was allegedly carried out by a total of eight suspects, four of whom were said to be from North Korea's foreign and security ministries, South Korean intelligence officials told its lawmakers, according to a Reuters report earlier this week. "Among eight suspects in this case four are from the ministry of state security and two who actually took action are from the foreign ministry," Lee Cheol-woo, one of the lawmakers briefed by South Korean intelligence, told reporters. However, North Korea has denied the accusations.

After the murder, the Malaysian government said Friday it has been reviewing diplomatic relations with North Korea because of the use of the banned VX nerve agent. Malaysian Foreign Minister Anifah Aman said that North Korea "insulted Malaysia" at an unofficial meeting of the foreign ministers of the Association of Southeast Asian Nations in the Philippines last week, Nikkei Asian Review reported.