Japan is asking South Korea to hold a summit on the sidelines of the Asia-Europe Meeting, which starts July 15 in Mongolia, a source familiar with Japan-South Korea relations said Tuesday.
South Korea has yet to make a clear reply to the proposal.
A senior South Korean official in the presidential office told reporters earlier Tuesday that progress seems not to have been made on the issue. But the source left open the possibility, saying Prime Minister Shinzo Abe and President Park Geun-hye may meet even if only for a short time.
The ASEM will run for two days in Ulan Bator.
In such a meeting, the two leaders would be expected to discuss North Korea's nuclear and missile development programs and vow to seek firm solidarity with the United States in coping with Pyongyang.
Abe and Park held a summit last November in Seoul, the first time since they took office, and also met in Washington in March.
In a major turnaround in bilateral ties, South Korea and Japan reached a landmark agreement last December on the "comfort women" forced to work in wartime brothels for the Japanese military.
Tokyo pledged to provide ¥1 billion (about $9.8 million) for a new South Korean foundation aimed at helping the aging women.
The deal has been criticized by some of the victims, as well as South Korean activists and opposition parties, who have called on the Japanese government to admit legal responsibility for compensation.