Ceremonies have begun to mark the removal of a buffer zone that has divided Ivory Coast for five years.
Peacekeepers have stopped the rival armies clashing
A bulldozer knocked down a UN military check-point, leading to cheers as vehicles moved freely into the zone.
President Laurent Gbagbo and former rebel leader, Prime Minister Guillaume Soro, jointly inspected government troops and former rebel soldiers.
They will form a joint force to patrol the zone separating the rebel-run north from the loyalist-controlled south.
The 600km-long zone has been patrolled by 11,000 French and UN peacekeepers to keep the rivals apart.
A BBC correspondent says this is portrayed as a major step towards reunifying the country and holding elections.
He says there has been an extraordinary thaw between President Gbagbo and Mr Soro - who was last month named as prime minister, following a peace deal between the two men.
The BBC's James Copnall in Abidjan says the buffer zone had effectively split Ivory Coast into two countries.
Travelling between the government-controlled south and the rebel-held north has been possible, but it has never been easy thanks to road blocks and mutual suspicion, he says.
Now the confidence zone is to be dismantled, though the process will take several weeks.
The UN and French will withdraw to 17 observation posts and the loyalist and rebel armies will mount joint patrols.
But the man Mr Soro replaced, Charles Konan Banny, has his doubts about the peace process.
He spoke for many Ivorians when he told the BBC he feared both President Gbagbo and Mr Soro had hidden agendas which would compromise the chances of free and fair polls.