South Korea and France have reportedly made headway in negotiations to have ancient Korean books that were looted by French soldiers in the mid-19th century returned to South Korea.

Korea’s ambassador to France, Park Heung-shin, said Tuesday that he continues to hold consultations on the matter with French officials, adding that the two sides have narrowed differences on key contentious issues.

Park made the comment during a parliamentary inquiry on the Korean Embassy. Park said he is seeking to reach an agreement on the issue before the G20 summit opens in Seoul next month.

Park stressed that a planned summit between the leaders of the two countries that will take place on the sidelines of the G20 gathering will provide a key opportunity to settle the issue regarding the ancient books.

The “Oegyujanggak” books are currently preserved at the National Library of France. “Oegyujanggak," or “Outer Gyujanggak,” was an auxiliary facility of the “Gyujanggak,” which was the royal library during the Joseon Dynasty. The books were taken from the facility on Ganghwa Island during the French invasion of the island in 1866.