However, she said the pact "cannot be a true solution for the victims of Japan's wartime sex slavery".
Japan said any attempt to revise it could damage relations.
He added that it had excluded the opinions of the victims.
"(Seoul) is expected to urge Tokyo to take responsible steps vis-a-vis wrong (parts of the) deal in line with the seriousness of the comfort women issue and the spirit of the principles of universality for mankind", the source added.
The Korean government also plans to raise a fund equivalent to the 1 billion yen ($8.87) transferred by Tokyo to a foundation formed under the 2015 agreement for the victims of the Japanese Imperial Army's forced recruitment of young women into sexual slavery before and during World War II, who are euphemistically referred to as comfort women. "I think the victims will forgive and this issue can be completely resolved when Japan accepts the truth, make a heartfelt apology to the victims, learn lessons and cooperate with the global community in preventing recurrence of such a thing".
The comfort women issue has been a regular cause for contention between Japan and neighbours China and North and South Korea since the war.
Japan paid 1 billion yen into a fund supporting the victims and extracted promises from Seoul to remove statues honoring the victims from the vicinity of Japanese diplomatic missions.
"It is an undeniable fact that that the 2015 deal was an official agreement reached between the two countries, and we will not demand a renegotiation from the Japanese government", Kang told reporters at the Ministry of Foreign Affairs in Seoul.
Kang also revealed that Seoul will put aside 8.9 million USA dollars to help the victims rather than use the equivalent amount offered by Tokyo in the 2015 deal as a compensation fund - as for the money from Tokyo, they plan to have further discussions on what to do with it. Seoul also called on Tokyo to make efforts of their own accord to help ease the victims' suffering, and give them a honest, voluntary apology.
"Truth and justice are key to resolving the issue, but it is not possible to renegotiate the deal".
There are 31 surviving women registered with the government, a foreign ministry official said.
"We can't accept Korea's request for us to do more, even though the two countries confirmed that the deal was final", Japanese Foreign Minister Taro Kono said. Japan's chief cabinet secretary, Yoshihided Suga said that Tokyo will "not move a millimetre on the deal" (FT.com, may be behind a paywall).
South Korean President Moon Jae-in won an election a year ago after promises on the campaign trail to renegotiate the deal.
But it said it would no longer use Japanese money to compensate the survivors.
"In a positive aspect, it is not bad that the government set aside its own budget for the victims", said Kim Sung-han, a former South Korean vice minister.
Moon had lambasted the agreement on the campaign trail and was elected president in May after Park was impeached and jailed over a massive corruption scandal.