Prime Minister Shinzo Abe is considering attending an event in Tokyo to mark the 50th anniversary of the normalization of diplomatic ties between Japan and South Korea, a government source said Thursday.

Abe’s final decision on attending the June 22 event organized by the South Korean Embassy will hinge on whether South Korean President Park Geun-hye will attend a similar commemorative event to be held the same day by the Japanese Embassy in Seoul, the source said.

The two countries will be holding the events amid strained bilateral ties due to conflicting views on Japan’s 1910-1945 colonial rule of the Korean Peninsula and the Takeshima territorial row. The issue of the Korean “comfort women” who were forced to provide sex at Japanese military brothels before and during World War II is a particularly bitter issue.

The tensions have kept Abe and Park from holding a formal one-on-one meeting since either took office.

Senior diplomats held talks in Tokyo on Thursday. They discussed who should attend the anniversary events in Tokyo and Seoul, among other issues.

Chief Cabinet Secretary Yoshihide Suga told a news conference earlier in the day that the Abe government had sent invitations to officials from both countries’ governments, but nothing had been decided yet on whether Abe and Park would attend the two separate commemorative events.

Meeting for an eighth round of talks, the senior diplomats are believed to have been setting the stage for South Korean Foreign Minister Yun Byung-se to come to Tokyo for the anniversary event and to hold talks with his counterpart, Fumio Kishida, ministry sources said.

Japan was represented at the talks by Junichi Ihara, head of the Foreign Ministry’s Asian and Oceanian Affairs Bureau, and South Korea by Lee Sang-deok, director general of the Northeast Asian Affairs Bureau.

During their talks, Ihara and Lee also discussed the issue of former South Korean comfort women.

“We conveyed each other’s positions and agreed to continue talking to find a common ground,” Lee told reporters after the meeting.

He said that they will hold their next round of talks next month.

When they last met in March, they apparently made no significant headway on the comfort woman issue.

South Korea has repeatedly demanded that Japan settle the issue in a way that is acceptable to surviving victims, such as through an official apology and compensation.

Japan maintains that all compensation issues were settled under the 1965 bilateral treaty that normalized diplomatic ties.

Ihara and Lee also discussed a recent issue of mutual interest — the proposed UNESCO World Heritage listing of historical industrial sites in Japan, Yasuhide Nakayama, a senior vice foreign minister, said at a news conference held after the meeting.

Japan aims to register the “Sites of Japan’s Meiji Industrial Revolution,” which represent Japan’s industrialization in the late 19th to early 20th centuries, on the World Heritage list.

South Korea contends that about 60,000 Koreans were conscripted to work at some of the 23 proposed sites during World War II.

Japan, however, argues that the period covered by the proposed listing is from the 1850s to 1910, well before the time of conscripted labor usage. Japan has also asked South Korea not to politicize the matter.