Historical differences have driven a sizable wedge between Korea and Japan.
President Park Geun-hye has yet to sit down for summit talks with Japanese Prime Minister Shinzo Abe that is in a bilateral framework.
A Korean diplomat says bilateral relations will likely remain at a standstill unless Japan owns up to its past wrongs.
Our foreign ministry correspondent Hwang Sung-hee reports.
South Korean Ambassador to the United States Ahn Ho-young says it's basic common sense that Japan should apologize for its wartime atrocities before bilateral summit talks occur between the nation's leaders.
In a keynote speech at a seminar in Washington on Tuesday, Ahn said Seoul would elevate its relations with Tokyo only when it's ready to acknowledge the past as it is.
The diplomat said such action was necessary to ensure that a summit between the two leaders leads to improved ties.
Relations between Korea and Japan have hit a new low in recent years as the Abe administration continues to distort historical facts.
President Park Geun-hye refuses to sit down with her Japanese counterpart until he apologizes for Japan's sexual enslavement of Korean women in early 20th century.
The two leaders have not held a bilateral summit since either took office.
Japan understands that settling the sexual slavery issue is key to cooling tensions with Korea, according to a senior foreign ministry official in Seoul.
He told reporters Tuesday that the Korean and Japanese foreign ministers agreed in Myanmar earlier this month on the need for progress in their monthly high-level talks aimed at resolving the sex slavery issue.
As for the past three rounds of talks that were held, the senior diplomat made clear that it's too early to talk about whether any progress is being made.
Hwang Sung-hee, Arirang News.