Incredulity followed the Nobel Peace Prize award on Friday for U.S. President Barack Obama, less than a year after his historic election and as he grapples with two wars.

The move was seen as an expression of high expectations by the world that the country’s first African—American president will move forward on a raft of international issues, rather than as acknowledgement of what he has accomplished in just nine short months.

Those issues include the nuclear crisis with Iran, the Middle East peace process and the wars in Iraq and Afghanistan.

At home, the award comes just as the U.S. public’s honeymoon with Obama is coming to an end, with growing impatience with continuing economic malaise and ongoing loss of life of U.S. soldiers in Afghanistan.

“It’s very clear they have wanted to encourage President Obama to move on those issues he has been talking about,” Martti Oiva Kalevi Ahtisaari, the 2008 peace prize winner, told CNN.

It was unusual that the award went to a sitting U.S. leader. The last U.S. president to receive the prize while in office was Woodrow Wilson in 1919 for his leadership in founding the League of Nations after the horrors of World War I.

Like many observers, Kristian Berg Harpuiken of the Sweden—based International Peace Research Institute was surprised by and doubtful over the wisdom of the choice.

“It’s a possible sign that he has the world’s backing,” Mr. Harpuiken told CNN.

Thorbjorn Jagland, the chairman of the Norwegian Nobel Committee and a former prime minister of Norway, denied that the committee struggled with the decision, pointing out that the organization had also made awards in the past to German leader Willi Brandt and Russian leader Mikhail Gorbachev as they started their peace initiatives that led to the fall of the Berlin Wall.

“We want to support what (Obama) stands for,” Mr. Jagland told CNN.

Meanwhile, the U.S. president has started receiving accolades from world leaders.

The selection of Mr. Obama as the winner of the 2009 Nobel Prize for Peace was "exciting and far-sighted," Norwegian Prime Minister Jens Stoltenberg said on Friday.

"It is an important prize since it can help contribute to make the president's visions into effect," Stoltenberg added, saying the U.S. president had "reached out a hand to solve conflicts with peaceful means."

Former South African President Nelson Mandela congratulated Mr. Obama on being the surprise winner of this year's Nobel Peace Prize, and called on Mr. Obama to use the honour to fight against poverty.

The Nelson Mandela Foundation, in a statement issued on behalf of the 91-year-old anti-apartheid icon, said it "welcomes the awarding of the Nobel Peace Prize to President Barack Obama."

"We trust that this award will strengthen his commitment, as the leader of the most powerful nation in the world, to continue promoting peace and the eradication of poverty."

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