French Foreign Minister Jean-Noël Barrot has arrived in Congo's capital Kinshasa, an official at the presidency said on Thursday, as Rwanda-backed rebels consolidated control of Goma in the east of the African country.

"The Minister of Foreign Affairs of France will be received in the next few minutes by the president," said Giscard Kusema, deputy director of press for President Felix Tshisekedi.

A French diplomat confirmed that Barrot had landed in Kinshasa, days after M23 rebels, with support from Rwandan troops, marched into Goma and were continuing their offensive southwards in the biggest escalation since 2012 of a decades-old conflict.

France's foreign ministry declined to comment.

Rioters stormed foreign embassies including the French mission in Kinshasa on Tuesday, drawing tear gas from police, in an eruption of protests over the conflict in the east.

Barrot said in parliament on Wednesday that there had to be diplomatic solution to the crisis and that Paris would do all it could to help mediation efforts between the two sides.

Rwanda has drawn an international backlash over its actions in Congo, with the United Nations warning the violence could spill over into a regional war.