Russia on Monday blocked a United Nations Security Council draft resolution, under negotiation for many months, that for the first time would have defined climate change as a threat to peace.

The resolution, which enjoyed wide-ranging support, would have significantly expanded the criteria used by the most powerful U.N. agency to justify intervening in armed conflicts around the world.

Russia¡¯s derailment of the measure underscored the challenges faced by the United Nations in uniting the global community to combat climate change, which Secretary-General Antonio Guterres and others have called an existential threat.