Violent protests should not be allowed to stop major international summits going ahead, Tony Blair said on Sunday.

Speaking as the G8 summit came to a close, Blair stressed that world leaders should stand their ground and not scale-down gatherings as a result of violence.

Blair said the rioters were seeking to "stand the whole principle of democracy on its head".

"So these guys can come and riot, and we the democratic leaders should conclude from that that we should never meet again. Not as far as I'm concerned," he said.

His comments came as the Canadian prime minister suggested next year's summit should be scaled down in the wake of the violent scenes played out on the streets of Genoa. Jean Chretien, who hosts the next G8 summit, is likely to switch the summit from Ottawa to a more secure resort deep in the Rocky Mountains.

Blair defended the public's right to take to the streets but warned that violence could play no part in legitimate protests.

"We stand firmly by the right of people to demonstrate and protest peacefully. It is a shame that the vast majority had their protests hijacked by a small minority who were prepared and came specially prepared to use violence," he said.

He said it was a "tragedy" that one protester had been killed during clashes between the police and protesters.

Challenging claims that major summits had become overblown junkets where little of substance was actually achieved, Blair said he had no interest in the "trappings" of such gatherings.

"Where the summit is, how big the delegations, what we eat at the summit, that is all to me irrelevant. What the trimmings and trappings are, I have no interest in that at all," he said.

Blair said progress had been made on issues of critical importance to the world. Blair said the summit had reached an "agreement on the ends" required to combat climate change.

He also welcomed the progress made on combating killer diseases such as Aids and HIV in Africa.

G8 leaders agreed to a £100 million fund to combat Aids, which is wreaking havoc throughout sub-Saharan Africa, the prime minister said.

"Whatever the focus on the protests, the achievements are big steps forward on the financial system for the world, on global trade, on climate change and above all the agreement of a plan for Africa.," said Blair. "It gives us the best opportunity literally for generations of giving Africa the hope and opportunity it needs for the future."