The former president of Finland, Martti Ahtisaari, has received the Nobel Peace Prize at a ceremony in the Norwegian capital Oslo.
The veteran mediator has over the past 30 years helped resolve conflicts in troublespots such as Indonesia, Namibia, Northern Ireland and the Balkans.
In his acceptance speech, he stressed the need to resolve one of the world's most drawn-out conflicts, calling on US president-elect Barack Obama to give priority to a comprehensive peace deal in the Middle East when he takes office.
Mr Ahtisaari said all conflicts can be settled, and there are no excuses for allowing them to become eternal.
He insisted that to make peace in the Middle East a wider perspective was needed.
In addition to the United States, the European Union, Russia and the United Nations also needed to be involved in reaching the accord, which he said should stretch "from Israel and Palestine to Iraq and Iran."
In Europe, Mr Ahtisaari played a key role in bringing an end to hostilities in the breakaway Serbian province of Kosovo in 1999, before attempting in vain from 2005 to 2007 to broker an agreement between Belgrade and Pristina on the province's status.
Kosovo, inhabited mainly by ethnic Albanians, unilaterally declared its independence from Serbia in February this year, to the dismay of Belgrade and its allies in Moscow.
Mr Ahtisaari said at a press conference in the Norwegian capital on Tuesday that he believed Kosovo's independence was irreversible.