'Two years ago we heard that President Barack Obama had won the Nobel Peace Prize, but is he defending peace in the world now, or isn't he instead fomenting violence?' Morales told reporters, days after Obama ordered the bombing of Libya military targets as part of an UN-approved effort to protect civilians.

'How is it possible to give the Nobel Peace Prize to someone who has launched an invasion, a bombing? It's a violation, an assault, an aggression,' said Morales, one of Latin America's most left-leaning leaders and a vocal critic of the United States.

'Obama is the leader of group of thugs who led an assault and an invasion - and that has nothing to do with defending human rights,' he declared.

Obama receive the prize in December 2009, less than a year after taking office.

In his acceptance speech in Oslo, Obama referred to himself as 'the commander-in-chief of a nation in the midst of two wars' and said armed conflict was at times necessary.

Obama gave his $US1.4 million ($A1.4 million) Nobel Peace Prize award money to 10 charities, including groups working on Haiti relief and supporting military families.