(CNN) -- French President Nicolas Sarkozy insists Europe will never give up on the euro, despite widespread fears for the currency's future.

Economists have voiced concerns that ongoing debt crises in Greece, Ireland, Spain and Portugal could spell the end of the single European currency.

But in an address to the World Economic Forum in Davos on Thursday, Sarkozy made clear he believes the euro will survive despite its current difficulties.

"We will never abandon the Euro. Never! "Euro spells Europe, the euro is Europe. Europe has meant 60 years of peace on our continent. We will never abandon that."

Sarkozy said the euro was central to European unity.

"If Europe has become the world's most stable, most peaceful continent, it is because we, our predecessors built the European Union.

"To imagine that we might pull out of that is to ignore the fact that as people who have been at each other's throats for centuries, we now have one wish, and that is lasting peace."

The French President said the euro's member nations could not even consider allowing the currency to falter.

"The consequences of the euro failing would be so cataclysmic, we can't even imagine them, we can't even play with this idea."

And he had a warning for currency speculators and those apparently keen to see the euro's troubles continue.

"For those who wish to wager against the euro: Be careful how you invest because we are determined."

Sarkozy also took on the U.S., telling his "friends across the Atlantic", that despite the U.S. dollar's status as the world's dominant currency, the country did not have the right to make all the rules.

"Nobody wants to weaken the dollar -- the world needs the dollar. The dollar is there, it will continue to be the world's dominant currency.

"But dominant currency doesn't mean the only currency."

He said it was only natural that each nation would act in the best interests of their own currency, because it was not simply an economic issue, but a political one.

Sarkozy, who holds the presidency of both the G-8 and the G-20 in 2011, called on the world's nations to rethink their old ways of working.

"We entered into the 21st century 11 years ago already, and we are still functioning according to the rules of the twentieth."

He said it was "madness" that Africa, South America and India did not hold a permanent seat on the U.N. Security Council, "this doesn't make any sense."