South Africa often uses its diplomatic heft to position itself as defender of the "global south" on the world stage, but the deaths of 13 of its soldiers in eastern Congo fighting have exposed an inability to project hard power in its own backyard.

Kagame's comments clearly suggested that he wants South Africa to back off from DR Congo, where its military involvement dates back to the late 1990s. It first joined the UN's peacekeeping mission, Monusco, following the end of the racist system of apartheid in 1994.

Four more South African soldiers have been killed in fighting with M23 rebels in the Democratic Republic of Congo, the government said, taking the number of South African peacekeepers killed to 13 since the conflict escalated last week.

Four more South African soldiers were killed in fighting in the eastern Democratic Republic of Congo, raising the death toll to 13.