Tamil Tiger rebels encircled in a tiny strip of land by Sri Lankan troops are still putting up stiff resistance despite calls for their surrender, the military said on Thursday.
The army said the guerrillas controlled a mere 10-12 square kilometres (around four square miles) of territory on the northeast coast, where thousands of civilians are still trapped by the fighting.
Brigadier Udaya Nanayakkara, the island's military spokesman, said the Tigers were using artillery and tanks.
"There are sporadic clashes but our priority is to get the civilians out. We can finish them off very quickly after the civilians get out of the way," he said.
"We can claim we have completely defeated the Tigers when we have captured the remaining area."
The rebels have been repeatedly accused of using civilians as human shields. Around 100,000 people have managed to escape rebel-held territory this week, and it was unclear how many were still trapped in the war zone.
President Mahinda Rajapakse has told the rebels to give up, but has ruled out any amnesty for rebel leader Velupillai Prabhakaran, who has led a ruthless decades-long battle for a separate Tamil homeland.
The UN Security Council president also said on Wednesday that the Liberation Tigers of Tamil Eelam (LTTE) must now give up.
"We demand that the LTTE immediately lay down arms," said the current council president, Mexico's UN ambassador Claude Heller, following an informal discussion on Sri Lanka by the council.
There was no immediate comment from the rebels.
The Sri Lankan army has made steady advances in recent months, slowly beating back the guerrillas who at one time controlled more than one-third of the island, and the government insists the rebels are now all but finished.
On Wednesday, two senior Tiger officials -- including their spokesman and main contact with the outside world, Velayudam Dayanidi -- surrendered to government forces.
This was seen as a blow to the LTTE, whose members are under orders to commit suicide by cyanide capsule rather than give themselves up.
But as the army has slowly pinned the guerrillas down in the narrow strip of coastal jungle, the international spotlight has focused on the fate of civilians caught up in a conflict that has claimed an estimated 70,000 lives.
State television has shown thousands of people waiting for food; desperate civilians trudging through waist-deep water to get to safety; and a young woman giving birth on a bus carrying displaced civilians away from the war zone.
"This is such a terrible humanitarian tragedy," US Secretary of State Hillary Clinton said.
"We have been pressing the Sri Lankan government for a halt in the fighting so that we could secure a safe passage for as many of the trapped civilians as possible."
The Tigers have acknowledged losing ground but have accused the government of killing 1,000 civilians in recent days. The military for its part said fleeing non-combatants were fired on by the rebels.
The rival claims are hard to verify as independent reporters are not allowed into the area, but aid agencies have painted a grim picture.
The International Committee of the Red Cross says the situation in the north is "nothing short of catastrophic," while Doctors Without Borders (MSF) said one hospital in the northern Vavuniya area was "saturated" with patients coming from the conflict area.
"The buses are still coming and they're actually unloading dead bodies at times as some wounded people died on the way," said Karen Stewart, an MSF mental health officer.