Sri Lanka's President Mahinda Rajapaksa says Tamil Tiger rebels will be 'completely defeated in a few days'.

Mahinda Rajapaksa made the comments in an speech to the nation on the country's national day.

Separately, the government and rebels have come under more pressure to declare a ceasefire in the ongoing war.

This will allow casualties to be evacuated from the war zone in the northeast of the country.

In his speech, Mr Rajapaksa said the rebels' defeat was imminent.

"Today we have been able to nearly destroy terror," he said.

"At this moment I urge all Sri Lankans from all communities who fled the country because of the war to return to their motherland."

Meanwhile, a joint statement issued following a meeting between the US Secretary of State, Hillary Clinton and the British Foreign Secretary, David Miliband, said there should be a truce so that humanitarian aid could be allowed in.

The Sri Lankan government has previously ruled out any ceasefire and has vowed to crush the rebels.

The Tigers have said they will not lay down their arms until they have a "guarantee of living with freedom and dignity and sovereignty".

Earlier Sri Lanka's key international donors, the United States, Japan, Norway and the European Union called on the Tamil Tiger rebels to consider laying down their arms to avoid more civilian casualties.

The group specifically called on all combatants not to fire on a hospital in Mullaitivu district which has been shelled repeatedly.

The BBC's Ethirajan Anbarasan in Colombo says this is the first time the influential quartet has issued such an appeal to the Tamil Tigers.

It is also the first international acknowledgement that the rebels may be near to defeat.

Sri Lanka's government says it is close to defeating the rebels. There was no immediate response from the Tigers.

Up to 250,000 civilians may be trapped by the fighting.

In a joint statement, Sri Lanka's key international donors expressed "great concern" for the plight of civilians.

The statement called on all combatants not to fire on a hospital in Tiger-held territory which has been shelled repeatedly.

The Red Cross says the hospital in Puthukkudiyiruppu town in Mullaitivu district has been hit five times in the past few days, leaving at least 12 civilians dead. One strike was on a paediatric ward, it said.

The hospital is one of the last functioning health facilities in the area.

The government says it is not responsible for the attacks and has told civilians to leave the war zone. Pro-rebel websites blame the army.

Bunker

Sri Lanka's military said there was no sign of the rebel leader Velupillai Prabhakaran in the bunker found in the north-east earlier this week.

The two-storey-deep bunker was found hidden in a coconut plantation in Mullaitivu district during fighting on Monday, the army said.

The ministry said the bunker had electricity generators, air conditioning and medical supplies.

There is no independent confirmation of any of the army's claims - journalists are not able to reach the front lines.

Sri Lanka's military says it has designated a safe zone for civilians in a 32 sq km buffer zone on the A-35 main road which links Paranthan and Mullaitivu.

The zone is inside a gradually shrinking rebel enclave north of Mullaitivu.