The United Nations mission in Ivory Coast says it will push for targeted sanctions against anyone found hindering the troubled peace process.
Some 10,000 peacekeepers are charged monitoring a buffer zone
UN mission head Pierre Schori told the BBC he would recommend the move after a New Forces rebel group announcment rejecting South African mediation.
Last year, President Thabo Mbeki was appointed mediator by the African Union to try to solve the Ivorian crisis.
The country has been split since rebels seized the north three years ago.
South African Deputy Foreign Minister Aziz Pahad said on Tuesday that the New Forces were blocking the peace process.
The New Forces' statement claims this shows the clear bias the mediation has shown to President Laurent Gbagbo.
Their statement, signed by spokesman Sidiki Konate, says they will no longer work with the South Africans.
The statement says that despite following Ivory Coast for nine months, the South Africans have not fully understood the country.
The New Forces also accused South Africa of selling weapons to President Gbagbo, in violation of a UN embargo, and said they might bring legal action.
The statement called on the President of Nigeria and the African Union, Olusegun Obasanjo, to move the peace process forward.
Finally, the New Forces said the most urgent issue to be resolved is that of identity.
The BBC's James Copnall in Abidjan says that many northerners, including New Forces fighters, do not have Ivorian passports. The issue of who can be considered Ivorian - is one of the building blocks of this crisis.
There are clearly other problems to be resolved too, if the country is to hold presidential elections.
They are due on 30 October, though President Gbagbo has already admitted they may be postponed from between one week and two months because of insufficient organisational material.
The New Forces and the opposition say legal reforms on identification, nationality and electoral laws have not been made correctly by President Gbagbo, but the South African mediators agreed with President Gbagbo on this issue.
In addition, the numerous militias who support President Gbagbo have not yet been dismantled.
Until the reforms have been made to their satisfaction, and the militias have been closed down, the New Forces say they will not disarm.