North Korea’s ambassador to Malaysia faced a deadline to leave the country Monday after authorities here declared him “persona non grata” and accused Pyongyang of trying to manipulate the investigation into the poisoning of Kim Jong Nam, the North Korean leader’s half brother, at a Kuala Lumpur airport. The Malaysian government on Saturday gave Ambassador Kang Chol 48 hours to leave the country after he refused to apologize for his strong accusations over Malaysia’s handling of the investigation into the Feb. 13 killing.