In the early years of his presidency, ties were strained between DR Congo and Rwanda, which accused its giant neighbour of not doing enough to remove ethnic Hutu militias involved in the 1994 Rwandan genocide from its territory. Their presence in what is now DR Congo has been used to justify Rwanda's repeated military involvement in its giant neighbour, going back to its backing of Laurent Kabila's rebellion.

The M23 was formed in 2012, vowing to stand up for the rights of ethnic Tutsis and to protect them against these militias, but also battling the Congolese army, under the control of Joseph Kabila.

From the start Rwanda was accused of backing them. It has always denied these allegations, as it still does despite overwhelming evidence.

However, relations later improved and Kabila's government worked with Rwanda against the Hutu militias.

Alex Adams, Africa programme director at the European Council on Foreign Relations, said Kabila's appointment as rebel leader could bring his interests into alignment with those of Rwanda's president, even though their objectives differ.

"Kabila wants to recover political influence nationally, while Kagame is primarily concerned with Rwanda's security and strategic position in eastern Congo. This is an alignment of convenience rather than a partnership built on deep trust," he said.

Policy analyst Mayala said Kabila's involvement could help Rwanda counter accusations that it was interfering in Congo's internal affairs.

"This is a former president. It's finally a Congolese rebellion," he said.

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