Congolese opposition head Etienne Tshisekedi called on citizens to "no longer recognise" Joseph Kabila as president, in a video released as the long-serving leader appeared set to stay on despite his mandate expiring.

"I am launching a solemn appeal to the Congolese people to no longer recognise the authority of Mr. Joseph Kabila, to the international community to no longer deal with Joseph Kabila in the name of the Democratic Republic of Congo," 84-year-old Etienne Tshisekedi, leader of the country's mainstream opposition party, said in the video released on YouTube overnight.