The prime minister of Ivory Coast's internationally recognised president, Alassane Ouattara, has said the time is right for a "rapid offensive" against the country's main city, Abidjan.
Guillaume Soro said days of clashes in the city had sown panic among troops loyal to incumbent Laurent Gbagbo.
Ivorians had to trust in Mr Ouattara's forces, Mr Soro added.
Earlier, the UN urged Mr Ouattara to investigate hundreds of deaths blamed partly on his supporters.
As many as 1,000 people were killed in the western town of Duekoue last week after fighting between forces loyal to Mr Gbagbo and Mr Ouattara.
UN peacekeepers are now protecting tens of thousands of civilians who have taken refuge in the compound of a local church.
Mr Ouattara's supporters have dismissed talk of a massacre.
The UN recognised him as president after a run-off vote in November, but Mr Gbagbo also claimed victory and refused to leave office.