One judge noted with surprise that Barack Obama "didn't look particularly happy" at being named the Nobel peace laureate. Another marvelled at how critics could be so patronising.

In a rare public defence of a process normally shrouded in secrecy, four of the Nobel peace prize jury's five judges have spoken about a selection they said was both merited and unanimous.

To those who say a Nobel is too much too soon in Obama's young presidency, "we simply disagree ... He got the prize for what he has done", said the committee chairman, Thorbjorn Jagland.

Jagland singled out Obama's efforts to heal the divide between the west and the Muslim world and to scale down a Bush-era proposal for a missile shield in Europe.