South Korean Foreign Minister Park Jin is expected to visit Japan sometime after its Upper House election slated for July 10, pushed back from his original plan of traveling later this month, sources familiar with the countries' bilateral ties said Wednesday.

The postponement apparently reflected Tokyo's concerns over the possible negative impact a conciliatory stance toward Seoul could have on voters ahead of the House of Councillors election, given the still frayed Tokyo-Seoul ties, according to the sources.

Initially, Park planned to visit Japan after returning from a four-day trip to the United States through Wednesday and before June 22, when campaigning for the Upper House election is set to begin in Japan.