Defense Minister Gen Nakatani visited the South Sudan capital Juba on Monday to hold talks with his counterpart, Kuol Manyang Juuk, and to inspect Self-Defense Forces personnel taking part in a U.N. peacekeeping operation.
Prime Minister Shinzo Abe is seeking to raise the SDF's overseas profile by giving them more such missions.
Before visiting South Sudan, Nakatani on Sunday met with SDF members dispatched to Djibouti in eastern Africa on an anti-piracy mission in the waters off Somalia.
Praising the troops' activities in Juba, Nakatani said, "The government attaches importance to the peacekeeping operations as a means of achieving peace and stability in the international community."
Japan sent Ground Self-Defense Force personnel to South Sudan in 2012 after the country gained independence from Sudan. Around 350 SDF personnel are currently posted there.
In December 2013, fighting in Juba forced the SDF at one point to limit their operations to providing support at U.N. facilities for people seeking shelter from violence.
The troops resumed operations outside the U.N. facilities in late 2014, engaging in infrastructure building and providing medical support in the war-torn country.
Last year, the U.N. Security Council expanded the mandate of the U.N. Mission in South Sudan through May.