Prime Minister Shinzo Abe is considering a trip to North Korea to help settle the issue of abducted Japanese citizens.
Pyongyang last week agreed to reinvestigate the fate of the missing Japanese nationals in exchange for Tokyo relaxing some sanctions.
Foreign Minister Fumio Kishida said Tuesday the government is now studying whether a visit by Abe could help conclude the matter.
The trip would be controversial, since Japan does not have diplomatic relations with North Korea, in part because of the abduction issue.
North Korea acknowledged in 2002 that it abducted 13 Japanese citizens to teach its spies about Japanese culture and language.
Five of the abductees were returned. The North said the rest are dead, but many in Japan suspect that dozens more were kidnapped.
Pyongyang's acknowledgement in 2002 followed a visit to North Korea by Japan's then prime minister, Junichiro Koizumi.