IRISH troops are to be deployed alongside British soldiers in a peacekeeping team for the first time.
They will join forces in a new EU training mission in Mali.
Their role is to provide members of the Malian armed forces with military training and advice to improve their capacity to maintain security in Mali and restore the authority of the government there.
The Irish will work with members of the 1st battalion of the Royal Irish Regiment of the UK armed forces, based at Tern Hill in Shropshire.
The controversial move, announced yesterday by Defence Minister Alan Shatter, is expected to provoke a mixed reaction although the UK regiment includes a large number of personnel from the Republic.
It was expected the Irish would be deployed with a Nordic training team because of Ireland's joint deployment with military from Nordic countries in EU battlegroups in the past.
The Irish have worked with the British in an overseas mission previously but this is the first time the two forces will work side by side as a team.
The Defence Forces is expected to provide six military trainers and two staff officers for the mission in Mali.
Mr Shatter confirmed he will shortly seek the approval of the Cabinet for Irish involvement in the mission, which has an initial mandate for 15 months.
The mission is likely to be fully deployed by mid March with training starting in April. The trainers will not be involved in operations carried out by the Malian forces.
The Irish will be deployed for two tours of duty, four and a half to five months each.
The mission, including a force protection element, will comprise some 500 military personnel, of which 200 will be trainers. France will provide two of the four teams, a number of Nordic countries will form a third and the UK and Ireland will supply the fourth.
Conditions for the troops are expected to be similar to those encountered in Chad but the logistical support to be provided by the British will make deployment easier for the Irish.
Mr Shatter said, after an EU defence ministers meeting at Dublin Castle, that the provision of a joint UK/Ireland contingent was another step in the normalisation of relations between the two countries.
"In that sense, it is a historic step and provides a tangible manifestation of the very positive relationship and the mutual respect that now exists between our two countries.
"The fact that this first joint deployment is to a peacekeeping operation under a UN mandate and unanimously endorsed by the EU is also very pertinent in our historical context and reflects our joint commitment to international peace and security under the aegis of the United Nations", the minister added.
Mr Shatter said that, apart from standard military advice, training would also be provided to the Malian forces in international humanitarian law, the protection of civilians and human rights.
Defence Ministers were given a briefing on the mission by its commander, Brigadier General Francois Lecointre, and they agreed the mission would "impact greatly on the prevention of terrorism in the region and safeguard Europe and its citizens in the future".
A briefing was also given on the EU training mission in Somalia by its current commander, Irish Brigadier General Gerald Aherne.