Roh, 61, the party's floor leader, who had long been known for his clean and reformist image, killed himself earlier in the day by jumping from an apartment building amid an investigation into suspicions that he accepted illicit political funds.
"My heart is truly aching to hear the news of Rep. Roh's passing. Even though we were not in the same party, we worked together to make South Korean society more progressive," Moon said during a weekly meeting with senior secretaries.
"I deeply mourn Rep. Roh's death and would like to offer words of consolation to the bereaved family and the Justice Party," he said, adding that Roh, as a leader of progressive politics, has contributed greatly to broadening the horizon of South Korean politics. (Yonhap)