The UN says that supplies are urgently needed in the north
The United Nations in Sri Lanka says it will send food later this week to thousands of civilians displaced by fighting in the rebel-held north.
A UN spokesman said that 60 trucks would take 800 tonnes of food to the Wanni region by the end of the week.
The move comes as the army says that it is moving closer towards capturing the rebels' administrative capital of Kilinochchi after "intensive fighting".
About 70,000 people have been killed in one of South Asia's longest wars.
The UN's announcement comes two weeks after aid workers were ordered out of the north by the government.
The World Food Programme (WFP) now has permission to enter the Tamil Tiger-controlled Wanni district this week to deliver badly needed supplies to civilians, a UN spokesman in Colombo told the BBC News website.
Civilians have fled as government troops have attacked the Tamil Tigers
"We hope this will be the first of many such convoys," the spokesman said.
"We are not talking about starvation in the north, but we are talking about people whose ability to cope after heavy fighting over the last month has been seriously eroded."
The UN estimates that about 230,000 people have been displaced around the rebel strongholds of Kilinochchi and Mullaittivu in recent weeks.
The Sri Lankan Minister for Disaster Management and Human Rights, Mahinda Samarasinghe, told the BBC Sinhala service that the government was eager to ensure that supplies got through.
"We have decided to let the WFP in the main be a part of this convoy and also to allow them to take in their personnel along with these vehicles.
"We have told the UN that they can send up to three representatives with this convoy," he said.
Mr Samarasinghe said that the convoy was "just the beginning of a consistent strategy" that the government was putting in place to ensure that there was enough food supplies available to displaced people in the Wanni.
Meanwhile the army says that it is getting closer and closer to the strategically important town of Kilinochchi.
It said that air force helicopters attacked rebel bunker lines in support of ground troops and a strategically important road near the town was captured on Sunday after a seven-hour battle.
The government bars most journalists from areas where the fighting is taking place and the military's accounts cannot be independently verified.
There has been no comment on the latest fighting from the Tamil Tigers.