South Korea's new ambassador to Japan, Yoo Heung-soo, is optimistic about improving diplomatic relations with Japan and said he was looking forward to using his contacts to patch up ties when he takes his post over the weekend.

"As the Korean saying goes, 'Land hardens after a rainfall,' so relations in the future will become even better," Yoo, 76, said in an interview with a group of Japanese reporters Wednesday.

Yoo is scheduled to receive his credentials from President Park Geun-hye on Thursday before departing for Tokyo on Saturday. Yoo is a four-term lawmaker and also was chairman of the board of the South Korea-Japan Friendship Association.

The post has been vacant since June 15 after his predecessor, Lee Byung-kee, was appointed as new chief of the National Intelligence Service, South Korea's intelligence agency.

He expressed hopes of making the most of the contacts he has established so far and his extensive experience in dealing with Japan to seek a thaw in ties, which have soured over history issues and a territorial dispute.

Yoo said he lived in Kyoto as a child before returning to South Korea when he was a teenager.

In the interview, Yoo avoided touching on sensitive issues, such as the "ianfu," Japan's euphemism for the "comfort women" forced into sexual slavery by the Imperial Japanese military during World War II.

The thorny issue has hampered bilateral ties from advancing. In a symbolic move, Pope Francis on Monday greeted a group of former comfort women in at Myeongdong Cathedral in Seoul, where he shook hands with each of the seven women, some in wheelchairs, at the start of a Mass he led for peace and reconciliation on the Korean Peninsula.

Many of the surviving ianfu are in their 80s now.