Kim Jong Nam was killed in February 2017 when he was exposed to VX nerve agent at an airport in the Malaysian capital of Kuala Lumpur, a murder mystery that attracted worldwide attention and torpedoed a once warm diplomatic relationship between Malaysia and North Korea.The apparent expression of regret, which has been widely reported in South Korean media, was not an apology and would not constitute North Korea admitting responsibility for the killing.The North Korean government has vehemently denied it was responsible for Kim's murder, though the United States and Malaysian authorities have said North Korea was in fact responsible for Kim's death.Malaysia has charged four North Korean men and two women in Kim's killing. The women, Doan Thi Huong of Vietnam and Siti Aisyah of Indonesia, are currently on trial and face the death penalty if convicted. The men's whereabouts are unknown, and Interpol has put out red notices for each of them, asking governments around the world to return them to Malaysia to face trial.Doan and Aisyah have pleaded not guilty and claim they were duped by the North Koreans, who said they were TV producing filming a reality prank show. Prosecutors claim the women knew what they were doing. Hisyam Teh Poh Teik, a lawyer for Doan, told CNN he and the rest of his clients are considering using this new information to further impress the court of Doan's innocence. Teh said the Vietnamese Embassy in Kuala Lumpur and Vietnamese Bar association have not responded to his emails. North Korean Foreign Minister Ri Yong Ho visited Vietnam earlier this month, during which he and his Vietnamese counterparts had an "in-depth exchange of views and reached consensus on the issue of further developing the relations of friendship and cooperation between the two countries," North Korea's state-run news agency KCNA reported at the time. High-ranking Vietnamese officials told the South Korean government they are interested in hosting the expected second summit between US President Donald Trump and Kim Jong Un, the South Korean government source said.The timing of that summit, however, could be affected by when Kim decides to visit Seoul.During South Korean President Moon Jae-in's visit to Pyongyang in September, Moon told reporters he expected Kim to make an unprecedented visit to Seoul before the end of the year. Kim said that visit would happen "in the near future."But the probability of Kim Jong Un traveling to Seoul before the end of the year is "close to zero," according to an official with knowledge of the North Korean position on denuclearization told CNN."There are a lot of logistics involved, and the time window is so short, there's no time for both sides to agree on a plan and make preparations," the official said.If a Seoul summit does not take place, the official said it will likely affect the timing of a planned second summit between President Donald Trump and Kim, which Trump and his top advisers claim could happen in January or February.