(Reuters) -Here are some facts about NATO Secretary General Jens Stoltenberg, whose contract will be extended for a further year under a decision by the Western defence alliance:

* Stoltenberg took on the NATO role in 2014 after serving as U.N. climate envoy and prime minister of Norway. He led Norway between 2005-2013 in a coalition headed by the Labour Party, whose youth wing he had led in his 20s.

* He said in February he would not seek another extension of his tenure at NATO, having already had it prolonged three times. The last time he agreed to an extension, he had to give up an appointment as Norway's central bank governor.

* Stoltenberg was an anti-war activist in his youth who admitted to hurling stones at the U.S. Embassy in the 1970s in protest against the Vietnam war. He studied economics and was widely seen as a pragmatic centrist during a long career in Norwegian politics, including stints as finance minister and minister for trade and energy.

* He pushed his government to mediate, often in secret, on conflicts, including in Columbia and Afghanistan, and resolved a longstanding maritime border dispute with Russia.

* Stoltenberg was dubbed the "Trump-whisperer" for convincing Donald Trump to stick with NATO after the then-U.S. president complained that allies were spending too little on defence and threatened to pull out.

* The NATO leader has been credited with keeping the alliance together over Russia's invasion of Ukraine and striking a balance between those demanding maximum support for Kyiv and others urging more caution.

SOME COMMENTS ABOUT STOLTENBERG:

* "He thrives on compromise," Frank Aarebrot, professor of comparative politics at the University of Bergen and an acquaintance of Stoltenberg.

* "He's got a vast political network and good political intuition ... and he will also listen to civil society, not just people within the 'security cage'," said Jan Egeland, a former U.N. Under-Secretary General.

SOME COMMENTS BY STOLTENBERG:

"Russia's use of military force to modify its borders is unacceptable ... We will not live in a world where the strongest one prevails."

"NATO is determined to set the gold standard on addressing the security implications of climate change." - June 28, 2022

Asked in February this year what words of wisdom he would give to his successor, he replied:

"To keep Europe and North America together."

(Writing by Philippa Fletcher and Andrew Gray; editing by Gareth Jones)