TOKYO, Feb. 12 (Xinhua) -- Japanese Prime Minister Shinzo Abe on Tuesday demanded that the remarks made by South Korea's National Assembly speaker insisting that Emperor Akihito should apologize for the so-called "comfort women" issue be retracted.

"I was astonished. We've immediately conveyed through diplomatic channels that the remarks were extremely inappropriate and deplorable," Abe was quoted as telling a parliamentary committee on the matter.

The Japanese government has lodged a "stern protest" over the matter and demanded an apology, Abe told the committee.

Abe's comments were based on remarks made by South Korean National Assembly Speaker Moon Hee-sang to Bloomberg news service in an interview last week.

The "comfort women" issue refers to soldiers from the Imperial Japanese Army coercing and kidnapping girls and women and forcing them to work as sex slaves, servicing Japanese soldiers at military brothels during World War II.

Many of the women forced into sexual slavery by the Japanese aggressors came from the Korean Peninsula, as well as from other parts of Asia, including China.

Euphemistically, these sex slaves have come to be known collectively as the "comfort women".

Moon, in the interview, called Japan's Emperor Akihito "the son of the main culprit of war crimes," which was likely owing to the fact that Akihito's father was Emperor Hirohito who was in power before and during World War II.

Asked how Japan can mend its long-running dispute over wartime matters with South Korea, Moon was quoted as saying, "If a person like that (Akihito) holds the hands of the elderly former comfort women and says he's really sorry, then that one word will resolve matters once and for all."

While anger over the remarks have been fueled in Japan, Moon in further comments made on Monday underscored his stance, stating that an apology was necessary from "a leader in a responsible position in Japan," as reported by local media here.

He also maintained that Japan's previous apologies over the "comfort women" issue have been insincere.

Japanese Chief Cabinet Secretary Yoshihide Suga told a press briefing on the matter on Tuesday that Japan has been informed by the South Korean government that the report did not reflect Moon's "true intentions" to improve bilateral relations.

The bilateral ties between Japan and South Korea have been tested recently over a maritime and Air Force incident.

Japan said a South Korean warship directed fire-control radar at a Japanese Maritime Self-Defense Force P-1 patrol aircraft off the coast of Ishikawa Prefecture, central Japan, on Dec. 20.

A South Korean top court ordering Japanese companies to pay compensation for forced wartime labor during its brutal occupation of the Korean Peninsula has also added to bilateral disharmony of late.

In November last year, South Korea said that it would dissolve a foundation for "comfort women" funded by Japan under a 2015 agreement that was to purportedly settle the issue permanently.