During a parliamentary session Tuesday, Japanese Prime Minister Shinzo Abe called Moon's remarks "extremely inappropriate." The Tokyo government has also asked him to retract his words and apologize.

"It's not something I should apologize for," the speaker told reporters during an official trip to Washington.

"What I said was what I have always believed in and said for the past 10 years," he said. "I still think that's the fundamental way to address it."

Relations between Seoul and Tokyo have recently deteriorated to their worst in years due to military spats and issues related to Japan's 1910-45 colonial rule of the Korean Peninsula.

"When it comes to the comfort women issue, there is only one problem, and that is a sincere apology," Moon continued. "My basic message is that there's no reason for (Japan) to hold on to this issue for so long when it could be over with a sincere apology."

 Historians say as many as 200,000 Asian women, mostly Korean, were forcibly sent to front-line brothels to work for Japanese troops. The victims are euphemistically called "comfort women."

Moon expressed bewilderment over the Japanese government's calls for an apology, saying the least Abe could have done was to send a condolence wreath to Kim Bok-dong, a South Korean victim who recently died after gaining prominence for her campaign for women's rights.

"If (Abe) were to hold the surviving women's hands and say (Japan) was wrong, that he is sorry, then they would immediately say they forgive (Japan)," Moon said. (Yonhap)