Terry Waite spoke of advice given BBC corresponent Alan Johnston

Mr Waite, who was held hostage in Lebanon for more than four years, is president of the annual festival.

The eisteddfod was growing every year, said Mr Waite, and encouraged people to "shake hands across the world".

He spoke of his conversation with freed BBC journalist Alan Johnston who said Mr Waite's messages had been of comfort to him while in captivity.

Mr Waite is presiding over the festival until its climax on Sunday with a performance from tenor Jose Carreras.

Speaking about the eisteddfod he said: "How appropriate that Wales is able to host something in terms of music and the performing arts and use it towards worldwide understanding."

He said the crowds at this year's festival were bigger than he had seen before, adding: "It's getting bigger.

"The eisteddfod was founded with the principal aim of restoring relationships after World War II and attempted to get ordinary people to shake hands across the world. It's developed ever since.

Strong competition

"You get huge numbers of young people here from across the world - Israelis, Arabs, Muslims, Hindus - but somehow their differences are put to the background.

"The competition is very strong. But in some ways it's also very therapeutic and people manage to make friends."

He added: "We often feel in today's world that international understanding is only brought by politicians and diplomats, but I think we have to admit the politicians have made a pretty sorry mess of it.

"But ordinary people come here and they are able to make their own contribution and the end result is obvious to see."

Mr Waite met with pupils from Ysgol Llewellyn in Rhyl

Mr Waite spoke of the advice he had given to BBC journalist Alan Johnston on the day of his release after he was held captive for 114 days by the Army of Islam group.

"I spoke to him on the day of his release on the phone for about five minutes. He said he had heard my messages and was encouraged by them" he said.

"I told him to take time out now and give yourself a break.

"Alan will face a problem, which he will get over - being a news gatherer he will find it hard to adjust to being the news."

He added: "I find it inaccurate when I'm described as an ex-hostage and people forget I had a life before that. You cannot escape the fact that Alan was taken hostage but you can turn it round, it doesn't have to be a negative."

Asked why he thought so many people were still fascinated by his own story, Mr Waite said: "It's possibly because, on coming out, I refused to be defeated by it. I also tried to show that a negative experience can be turned around for a positive end."

Mr Waite spent Wednesday meeting competitors from across the globe and staff from the World Wildlife Fund Cymru.

The charity, of which Mr Waite is an ambassador, launched a carbon footprint calculator in Wales this week.