Bemba said he had "learned like everybody else, on the airwaves" about the outcome of the election.
"My surprise was great that the CEI did not, as arranged, notify the candidates of the results, thus enabling them to react within 48 hours," Bemba said.
|Thousands voted in DR Congo's first |
election for more than 40 years
The October 29 vote was the culmination of a peace process to end Congo's 1998-2003 war, in which Bemba led a rebel faction before joining a power-sharing government.
It was DR Congo's first full election in more than 40 years.
Speaking exclusively to Al Jazeera, Kabila said the election was a watershed for DR Congo.
"What has happened in the Congo in the last 2 to 3 months since the first phase of election is that we have turned a page… on the history of this country, which has been a country in turmoil for over four decades. Now we are going to start re-writing the history of the country," he said.
The vice-president's Union for the Nation coalition rejected the vote after a provisional result was announced. It alleges "systematic cheating" in the vote count and has questioned the credibility of the electoral commission.
It said on Tuesday that data collected by its own observers at polling stations showed Bemba led the election with 52.5 per cent of the vote.
The coalition said in a statement on Tuesday: "The Union for the Nation will not accept an electoral holdup that aims to steal the victory from the Congolese people."
Kabila, now Africa's youngest head of state, dismissed Bemba's complaints, saying: "This is nothing but agitation by politicians who either know they have lost the elections or don't even know what is going on because they have not been following the process."
Bemba's rejection of the results has stoked fears of further violence, but the city's streets were calm on Wednesday.
Soldiers loyal to the two candidates fought bloody street battles in August which killed at least 30 people after the first-round results were announced.
Four more were killed last Saturday when the two sides clashed once again.
A 17,500-strong UN force and a special European Union contingent have stepped up patrols in the country to head off any unrest.