UN Secretary General Ban Ki-moon has warned supporters of Ivory Coast incumbent Laurent Gbagbo not to attack his rival Alassane Ouattara's HQ.
An attack - threatened for Saturday - could spark civil war, he said.
Mr Ouattara, internationally recognised as winner of the presidential poll, is protected by UN soldiers in Abidjan.
Regional countries have threatened to oust Mr Gbagbo, but he says he will not leave voluntarily - and international pressure could trigger civil war.
"I do not believe at all in a civil war. But obviously, if the pressures continue as they have, they will push towards war, confrontation," he said in an interview for Euronews TV recorded on Tuesday and due to be broadcast on Friday.
He said his departure was not a guarantee for peace.
Mr Gbagbo says Mr Ouattara's victory is illegitimate. Both men have been sworn in as president.