Ichiro Ozawa, secretary general of the ruling Democratic Party of Japan, said Saturday that Japan must apologize for an "unfortunate period" in its relations with South Korea, referring to Tokyo's colonial rule of the Korean Peninsula from 1910 to 1945.

"There was an unfortunate period in modern history and it is a historical fact that Japan and the Japanese people must apologize for," Ozawa, who is in South Korea, said in a speech on bilateral ties at Kookmin University in Seoul.

Ozawa at the same time emphasized the need for the two countries to move forward on bilateral ties without being bound by the past.

"We need to make efforts to (build) goodwill and a friendly relationship, as well as solidarity by overcoming past issues," he said.

The former DPJ president reiterated his support for giving permanent foreign residents in Japan, including ethnic Koreans with special permanent residence status, the right to vote in local elections.

"We still have to settle some issues that remain unresolved in Japan and South Korea," he said. "Japan is in a position to make proposals in a positive manner on the matter."

Ozawa, who is believed to wield considerable influence over the new government, is in Seoul after visiting China for two days through Friday.