Seoul's Foreign Ministry says Vice Foreign Minister Choi Jong-kun summoned Japanese Ambassador to South Korea Koichi Aiboshi to the ministry Saturday morning to protest a recent remark made by a senior Japanese embassy official.

Choi told the ambassador that the undiplomatic and disrespectful remark seriously hinders efforts to advance bilateral relations. The vice minister urged Tokyo to take tangible, corresponding measures to prevent similar incidents from happening again.

The Japanese envoy expressed regret over the inappropriate remarks made by his deputy and promised to deliver Seoul's request to his government. 

Korean TV broadcaster JTBC reported Friday that Hirohisa Soma, deputy chief of mission at the Japanese embassy, made sexually indecent comments about President Moon Jae-in during a lunch meeting he held with a reporter.

Seoul and Tokyo have been in talks over Moon's possible visit to Tokyo to attend the Olympics opening ceremony and hold talks with Japanese Prime Minister Yoshihide Suga to discuss a range of pending issues.

In a press release to Korean media on Saturday, Ambassador Aiboshi said that he has sternly cautioned his deputy over the remarks that were "extremely inappropriate and very regrettable" as a diplomat.