The European Union has expressed concern over the fate of tens of thousands of civilians trapped in a Sri Lanka jungle enclave as rebel fighters vowed to make a last stand.
Thousands of Sri Lankans have been displaced by the fighting
Amid reports that the leader of Sri Lanka's Tamil Tiger rebels would hold his ground, the European Union's Czech presidency urged government and rebel fighters to protect civilians it fears will be used as human shields.
"The plight of the civilians still trapped by the fighting and who remain at extreme risk from the ongoing hostilities is our primary concern," the EU presidency said in a statement.
"The EU strongly condemns the killings of civilians and calls on all parties to take all necessary action to avoid further civilian casualties.
"The EU condemns in the strongest possible terms the LTTE (Liberation Tigers of Tamil Eelam) for the use of civilians as human shields.
"Both the government of Sri Lanka and the LTTE must fully comply with international humanitarian law and ensure the protection of civilians at all times."
The United Nations has estimated that up to 50,000 civilians are caught in the conflict area while the Sri Lankan government says it is closer 15,000-20,000. The Tigers insist the real figure is 165,000.
The EU backed the UN secretary general's decision to send humanitarian chief John Holmes to the temporary ceasefire zone Saturday, and called on Colombo to allow it unhindered access.
The UN estimates that as many as 6,500 civilians may have been killed and another 14,000 wounded in the fighting this year, diplomats said.
Independent verification of casualty figures is almost impossible as journalists have long been barred from the island's north, except when under strict supervision on trips organized by the military.
UN humanitarian chief visits war-torn island
Holmes was due in Sri Lanka Saturday to start a three-day mission which will focus on pushing the government to facilitate humanitarian missions in and around the conflict zone and to allow proper access to tens of thousands of displaced civilians, the UN said.
Sri Lankan troops freed thousands of captives after a battle with Tamil Tigers earlier this week
The plight and suffering of those caught in the fighting between government troops and Tamil Tiger rebels prompted US President Barack Obama's administration on Friday to urge an end to hostilities.
"We call on both sides to stop fighting immediately and allow civilians to safely leave the combat zone," the White House said in a statement.
The Sri Lankan government has so far resisted all calls to halt an offensive that is now on the brink of wiping out the LTTE, who have been fighting for an independent Tamil homeland since 1972.
The Tigers, once one of the most feared guerrilla organizations in the world, have seen their territory shrink to a sliver of land on the northeast coast estimated to measure 10 square kilometers (about four square miles).
The White House specifically demanded an end to any military shelling in a designated "safe zone" and access for aid groups and journalists to civilians who have escaped.
The LTTE issued their own call for foreign intervention, warning of "imminent" starvation among civilians and even suggesting that the situation could deteriorate into a crisis as appalling as that in the Darfur region of Sudan.
White House warns of a future of repercussions
The White House statement warned that the government risked sowing the seeds of future ethnic conflict on the Sinhalese-majority island.
The final push to end the Tigers resistance has proved particularly bloody
"It would compound the current tragedy if the military end of the conflict only breeds further enmity and ends hopes for reconciliation and a unified Sri Lanka in the future," the White House said.
Around 110,000 civilians managed to get out of the battle zone earlier in the week, overwhelming the government authorities handling relief operations.
The Sri Lankan government has been blocking most aid agencies from the war-torn north for months, and accuses UN agencies and NGOs of supporting the Tamil Tigers.
The UN Security Council president, Mexican Ambassador Claude Heller, said the Sri Lankan government should allow the UN and Red Cross to access all sites where displaced people were being registered and provided with shelter, according to UN spokeswoman Marie Okabe.
Despite this, Sri Lanka's Human Rights Minister Mahinda Samarasinghe welcomed the visit by Holmes, his second in as many months.
"We hope to have a constructive discussion with him," Samarasinghe said.
A French medical team was expected in Colombo Saturday to prepare the ground for a 100-bed field hospital to treat war victims.