The UN-approved deployment, which has been delayed by two months, was given the go-ahead yesterday after the French army agreed to provide helicopters and Italy pledged a field hospital.
An advance party of about 60 Irish Army rangers, engineers and mechanics will head out to Chad in the first week in February. Chad neighbours Darfur and has been flooded with refugees.
They will be followed in late February or early March by 180 troops who will set up a camp in eastern Chad.
A further deployment in March will bring the total of Irish troops to 400.
The soldiers will be part of a 4,000-strong force of troops from several EU countries, all of whom will be under the command of Lieutenant General Pat Nash from Limerick.
Human rights groups have criticised the delays in putting the troops on the ground as the refugees are under daily attack from rebel forces and guerrilla movements on both sides of the border.
Defence Minister Willie O’Dea said he was disappointed the mission could not have begun sooner, but he agreed with the stance taken by Lt Gen Nash, who said he would not deploy troops until the supports were in place.
Mr O’Dea said dangers remained for the Irish because of local antipathy towards their colleagues from France, a former colonial power there.
“The real danger is that they will tend to identify the UN force with the French, with whom they have issues,” he said.
“One of [the Irish troops’] jobs will be to make it absolutely clear that we are part of the UN mission: we are there to keep the peace, we are there for humanitarian reasons, we have no agenda and we are not part of backing up an ex-colonial power or anything of that nature.”