The plan to hold an election before the end of 2017 initially reduced tension between the government and the opposition.
The electoral commission said last November that it needed at least until July 2017 to register more than 30 million voters in a country similar in size to Western Europe, but with one of the worst transport and communication networks in the world.
Earlier this month, the death of veteran opposition leader Etienne Tshisekedi led to concerns about the country’s future.
Elections in DR Congo are often controversial. Last year, protests against moves to delay the presidential poll resulted in at least 50 deaths.
DR Congo has never had a smooth transfer of power since independence more than 55 years ago.
Mr Kabila took power in 2001 following the assassination of his father, Laurent Kabila. He has won two elections and the constitution bars him from running for a third term.