Over 200 UK military advisers are to be deployed to help train a west African fledgling force that will take over from French troops, with another 40 personnel offered to contribute to an EU training mission.
US allies will also provide back up by air.
Now it is thought that RIR troops, based at Palace Barracks in Holywood, Co Down - who were to be deployed to Afghanistan in April - could be the first soldiers to be tasked there instead.
Prime Minister David Cameron confirmed the government's cooperation as he arrived in Algeria on Wednesday in the wake of the hostage crisis which claimed the lives of six Britons.
Earlier this month, 135 oil rig workers were kidnapped by Islamist militants, including Belfast man Stephen McFaul, who later escaped.
Mr Cameron said his aim was to help the country "help itself" amid a growing threat from al Qaida-linked terrorists.
"The In Amenas attack and the situation in Mali reminds us of the importance of partnership between Britain and countries in the region," he told journalists.
Earlier this month, France launched air strikes in Mali against Islamist camps and mobile forces.
Their aim was to stop the rebel offensive as the Malian army was at the point of collapse.
Their Islamist opponents are heavily armed, very determined and very well organised, the French foreign minister stated.
The Islamist rebels control northern Mali, an area the size of France, and there are continuing fears they will use that control to destabilise the rest of west Africa, including neighbouring Niger, which is France's main source of uranium for its nuclear industry.
The French have now stabilised the situation enough to let African troops take over control.
In 2000, 11 Royal Irish soldiers on a training operation in Sierra Leone were kidnapped.
Five were released and the remaining six soldiers were freed by the SAS and the Parachute regiment.
In the Houses of Commons on Wednesday, UK Defence Secretary Philip Hammond made it clear that troops would not be sent for combat.
"The UK has a clear interest in the stability of Mali and ensuring its territory does not become an ungoverned space available for al-Qaida and its associates to organise attacks on the West," he said.
"We have defined very carefully the support that we are willing to provide to the French and the Malian authorities."