Around 120 soldiers from a largely Welsh regiment are being sent to support fellow British troops being redeployed in central Iraq.
The Welsh Cavalry is based at barracks in Cardiff
The army confirmed on Sunday that the squadron from The Queen's Dragoon Guards - the Welsh Cavalry - will be joining the Black Watch.
The Watch will be taking over operations from US forces.
Controversy has surrounded the decision to send British soldiers to the region.
But Defence Secretary Geoff Hoon said last week that the redeployment of British troops would last "weeks rather than months".
Preparations for the redeployment have been under way at the Black Watch's base in Basra for several days.
Major Charlie Mayo, the chief spokesman for the army in southern Iraq, told BBC Radio Wales that the troops would be getting to know the area and meeting the population.
"They're then going to be looking at deterring any criminal activity - and more importantly disrupting any of the anti-Iraqi forces, the terrorist activity which is taking place," he said.
"We know the area they're going to be moving into is slightly different to what we have down here in the south.
"But we mustn't forget that they were here fighting in the war last year so they are an experienced, well trained organisation and they've been in this sort of environment on other occasions.
"I wouldn't call it front line," he added.
"I'm confident that they'll be able to deal with whatever comes their way. All I ask is that their families stay strong for them."
The Welsh Cavalry has its home headquarters at Maindy Barracks in Cardiff and is based at Osnabruck in Germany.
It recruits mainly from Wales, Herefordshire and Shropshire.
They are undertaking their second tour of duty in Iraq.
During their first tour, which ended earlier this year, reconnaissance tanks from the Queen's Dragoon Guards were at the spearhead of British operations around Basra.
Members of the regiment were rewarded for their efforts in destroying more than 20 Iraqi tanks by being presented with the Commando dagger by the Royal Marines.