The European Union won the Nobel Peace Prize on Friday for its historic role in uniting the continent in an award meant as a morale boost for the bloc as it struggles to resolve its debt crisis.

The EU has been a key in transforming Europe "from a continent of wars to a continent of peace," Committee Chairman Thorbjoern Jagland said in announcing the award in Oslo.

"This is a message to Europe to do everything they can to secure what they've achieved and move forward," Jagland said, saying it was a reminder of what would be lost "if the union is allowed to collapse."

He praised the 27-nation EU for rebuilding after World War II and for its role in spreading stability after the 1989 fall of the Berlin Wall.

The prize, worth $1.2 million, will be presented in Oslo on Dec. 10. The decision by the five-member panel, led by Jagland, who is also secretary-general of the Council of Europe, was unanimous.

The EU won from a field of 231 candidates including Russian dissidents and religious leaders working for Muslim-Christian reconciliation.

But the EU is mired in crisis with strains on the euro, the common currency shared by 17 nations. The prize was a surprise given the EU's current woes.

Meanwhile, many Norwegians are bitterly opposed to the EU, seeing it as a threat to the sovereignty of nation states. "I find this absurd," the leader of Norway's anti-EU membership organization, Heming Olaussen, told the Norwegian Broadcasting Corporation.

"In Latin America and other parts of the world they will view this quite differently than they will from Brussels. The union is a trade bloc that contributes to keeping many countries in poverty."

Norway, the home of the peace prize, has voted "no" twice to joining the EU, in 1972 and 1994. The country has prospered outside the EU, partly thanks to huge oil and gas resources.

Janne Haaland Matlary, professor of International Politics at Oslo University, who has twice nominated the EU for the prize, praised the award.

"The European Union has been the most effective creator of peace in the world since its inception with the coal and steel union in the 1950s," she told Reuters. "Today it is unthinkable [there would be] military conflict between members in the EU."