On his final apppearance on Friday, Emperor Akihito - a marine biology enthusiast - visited London Zoo's aquarium.

The trip ended four days of public appearances, many of which attracted jeering and chanting demonstrators.

Former prisoners-of-war and civilian internees were demanding a full apology for their treatment in World War II, during which a third of all PoWs of the Japanese died.

'British-Japanese relations strong'

But the Emperor's press secretary, Kazuo Chiba, said he disagreed with those who believed the state visit had been counter-productive, re-opening old wounds resulting from the death and suffering of so many in Japanese prison camps.

The visit was controversial from the start

He said the trip had highlighted the economic, political, cultural, scientific and social ties between the two countries.

"The visit has proved the strength of present day British-Japanese relations. And, more to the point, it has been a successful celebration of the relationship brought up after the destruction by the war," he said.

He reiterated his statement that constitutional restraints prevented the Emperor meeting the veterans' demands for a full apology.

But he added: "I think it was very important that the Emperor expressed in an unprecedented way his feelings of deep sorrow and pain.

"The Emperor and Empress are very well aware of how the PoWs feel."

Mr Blair had called for "a warm welcome" for the Emperor

The visit began on Tuesday when former PoWs symbolically turned their backs on Emperor Akihito as he was taken by the Queen along The Mall in London to Buckingham Palace.

This was followed by similar protests in Wales and a demonstration by 50 veterans at Downing Street on Thursday when the Japanese party met Prime Minister Tony Blair for lunch.

Despite having received no apology, the PoWs are claiming a small victory after Mr Blair agreed to meet them.

Veterans turn their backs in Wales

They want the UK Government to back the campaign for an apology and compensation from Japan, saying that Mr Blair has done little during the state visit to help them.

The Prime Minister's offer to meet the veterans in the coming weeks came after they handed in a letter of protest at Downing Street, criticising the way the government has handled the issue.

Mr Blair's official spokesman said he had been unable to meet the veterans before the visit because of his commitment to the Northern Ireland referendum.

Speaking for the protesters, Keith Martin, chairman of the Association of British Civilian Internees Far East Region, said: "We are very pleased with the results of our demonstrations and campaigning. We have certainly got the message across."