By Anbarasan Ethirajan
BBC News, Colombo
The military has vowed to crush the Tamil Tigers
Sri Lankan government forces are in no hurry to storm a designated "safe zone" to pursue Tamil Tiger rebels in the north-east, the defence secretary says.
Gotabhaya Rajapakse's comments come a day after the military said it had confined the rebels to the so-called no-fire zone occupied by civilians.
Officials said more than 400 rebels, including five senior commanders, were killed in Mullaitivu district.
The rebels are yet to react to the military's version of events.
"We have no plans of going into the safe zone immediately. Our aim is to get the civilians safely out of the no-fire zone. So, we are watching at the moment," Mr Rajapakse said in an interview with the BBC.
His comments follow warnings by aid agencies that there may be heavy civilian casualties if the rebels fight back against the army's move to enter the safe zone.
Liberation Tigers of Tamil Eelam form in the north-east
India deploys peace-keepers to Tamil areas but they leave in 1990
President Premadasa killed by Tiger bomb
Attack on airport destroys half Sri Lankan Airlines fleet
Government and rebels agree ceasefire
Mahinda Rajapakse becomes president
Heavy fighting resumes
Army takes main rebel bases of Kilinochchi and Mullaitivu
It is estimated that there are between 40,000 and 100,000 civilians trapped in the safe zone, which is about 20 sq km of coastal area.
Mr Rajapakse, the most senior civilian official in charge of the war, said there were indications that civilians were lining up to leave the area.
More than 60,000 civilians have already fled the war zone in recent months and they have been housed in government-run relief centres and camps in the northern region.
"I don't think the Tamil Tigers can be a viable force any more. There are reports that there are lots of dissensions within the rebels. They can always surrender," Mr Rajapakse said.
The defence official once again denied allegations that security forces were firing into the safe zone.
The United Nations says more than 2,800 civilians may have been killed and 7,000 others injured in the fighting in the north-east in the last two months.
The government disputes these figures.
The clashes between security forces and Tamil Tigers have intensified in recent weeks as the security forces are in what they say is a final push to defeat the rebels and end nearly three decades of conflict.
Officials said the Tigers' last bastion, Puthukudiyiruppu region in Mullaitivu district, fell on Sunday after ferocious close quarter battles.