UN chief Ban Ki-moon on Friday congratulated US President Barack Obama on winning the Nobel Peace Prize, saying he embodies 'the new spirit of dialogue and engagement' in tackling world issues. 'The Secretary General wholeheartedly congratulates US President Barack Obama on winning the Nobel Peace Prize,' a United Nations statement said. 'President Obama embodies the new spirit of dialogue and engagement on the world's biggest problems: climate change, nuclear disarmament and a wide range of peace and security challenges,' it added. 'His commitment to work through the United Nations gives the world's people fresh hope and fresh prospects.' In a maiden speech to the UN General Assembly last month, Obama urged fellow world leaders to 'embrace a new era of engagement based on mutual interest and mutual respect.' 