The Democratic Republic of Congo could postpone its November 28 presidential election by a few days if logistics are not in place in time, the deputy head of the electoral commission said Monday.

Although Jacques Djoli insisted he was "99.9 percent" sure the polls would take place as scheduled, he added that "if we are not ready, we will ask for a few days and organise the elections on December 2 or 5."

During a visit to Brussels, Djoli, vice president of the National Independent Electoral Commission (CENI), was quoted as saying by the Belga news agency that voting material would be deployed on November 25.

Results will be compiled on December 5 and published on December 6, the expiration date of the term of President Joseph Kabila, who is seeking re-election.

The sheer challenge of installing voting materiel across the vast central African nation, and threats of violence, have raised doubts that the election can be held on time.

Congolese opposition leader Etienne Tshisekedi renewed a call on Friday for supporters to "terrorise" the country's security forces ahead of the November 28 polls and to free opposition activists from jail.

The European Union, United States, France and the United Nations, which has a large peacekeeping contingent in DR Congo, have all urged restraint and called on all sides to refrain from inflammatory statements.