South Korea's ambassador to Japan said Wednesday his country is closely watching whether the upcoming statement by Prime Minister Shinzo Abe to mark 70 years since the end of World War II contains key terms such as "remorse" and "colonial rule."

In a speech in Tokyo, Yoo Heung-soo, 77, said historical perceptions about Japan's wartime aggression is one of the issues that needs to be addressed for bilateral relations to benefit, and the content of Abe's planned August statement is critical to that end.

"Whether three key words are in the statement or not would determine how people perceive the statement," the former lawmaker said, referring to "aggression," "colonial rule" and "remorse."