The UN reported in December that up to 4,000 Rwandan soldiers are fighting alongside the M23 against the Congolese army and FDLR militia group. Rwandan President Paul Kagame has denied accusations that his soldiers are in DR Congo, though he has also simultaneously sought to justify its presence and right to defend itself.

Tshisekedi said conflict in the mineral-rich region over the last three decades had become a "battlefield for the predatory ambitions of some of our neighbours".

The Democratic Republic of Congo has urged Formula One to end talks with Rwanda over hosting a race, saying the Liberty Media-owned sport risks having its brand "smeared by a blood-stained association".

The Rwandan-backed M23 group on Friday advanced south after seizing the biggest city in mineral-rich eastern DR Congo, in violence that according to the United Nations has killed at least 700 people in less than a week.

The Democratic Republic of the Congo has asked the NBA, along with Formula 1 and numerous major European soccer clubs, including Arsenal, Bayern Munich and Paris Saint-Germain, to stop doing business with Rwanda as the conflict between the two countries deepens.

The NBA, whose recent Africa expansion is centered in Rwanda, is the latest to receive a letter from Congo officials; soccer teams Arsenal, Bayern Munich and PSG and racing's F1 got similarly worded pleas in recent weeks.

African country Congo has thrown a spanner in the works of neighbouring Rwanda’s clear plans to join the Formula 1 calendar. When Rwandan capital