Japan has supplied ammunition to South Korean troops serving in a UN peacekeeping mission in South Sudan, the Defence Ministry said on Tuesday, another step in Prime Minister Shinzo Abe's more assertive foreign policy. It was the first time Japan's post-World War Two Self-Defence Forces (SDF) have provided ammunition to another country, the Defence Ministry said, and is the latest move to ease self-imposed constraints on its military. Responding to a UN request, SDF engineering troops in South Sudan on the same operation supplied 10,000 rounds of ammunition to the South Koreans on Monday through the UN mission in South Sudan (UNMISS). Abe returned to power a year ago for a second term pledging a tougher stand against China, with which Japan is locked in a bitter territorial dispute over East China Sea islets, and to bolster Japan's defence posture. Relations between Tokyo and Seoul have also been strained by a separate territorial row and disputes over Japan's wartime history, including women - many Korean - who were forced to work in military brothels during World War Two.