Washington  - US Senator John McCain, who lost his presidential bid last year, said Americans should be happy that his campaign rival President Barack Obama won the Nobel Peace Prize.

"I think Americans are always pleased when their presidents are recognized by something on this order," McCain said Friday in broadcast remarks.

"We're proud when our president receives an award of that calibre," he said.

The centre-right Republican admitted he was "surprised" by the decision, which he said seemed to be based on the committee's expectations of Obama rather than on the Democrat's accomplishments.

Other Republican leaders were quick to turn the praise into criticism, questioning Obama's credentials for receiving the award.

"It is unfortunate the president's star power has outshined tireless advocates who have made real achievements working towards peace and human rights," said Michael Steele, the chairman of the Republican National Committee.

"One things is certain: President Obama won't be receiving any awards from Americans for job creation, fiscal responsibility or backing up rhetoric with concrete action," he said.

Democrats focused on congratulating Obama as a leader who has restored America's standing in the world after the eight-year presidency of George W Bush.

"In an age when the actions of one nation can affect the future of all nations, the president has recognized the need for global solutions to our most pressing challenges," said Nancy Pelosi, the speaker of the House of Representatives.

Former president Jimmy Carter, himself a Nobel Peace Prize laureate in 2002, also congratulated Obama as did fellow American and 1986 prize winner Elie Wiesel, the Romanian-born human rights activist who survived Nazi concentration camps.

"I confess surprise," Wiesel told National Public Radio. "I think the Nobel committee loves to surprise people."

He said the committee had its own rules and "may decide anything they want. They may decide that encouragement is part of the experiment." (dpa)