U.N. chief warns Ukraine war one of greatest challenges to international order

United Nations Secretary General Antonio Guterres addresses the United Nations Security Council during a meeting, amid Russia's invasion of Ukraine, at the United Nations Headquarters in Manhattan, New York City, New York, U.S., April 5, 2022. REUTERS/Andrew Kelly

U.N. Secretary-General Antonio Guterres warned the Security Council on Tuesday that Russia's invasion of Ukraine is one of the greatest challenges ever to the international order "because of its nature, intensity, and consequences."

Guterres said the war was putting even more pressure on the developing world, with more than 1.2 billion people particularly vulnerable to to spiking food, energy and fertilizer costs. "We are already seeing some countries move from vulnerability into crisis, and signs of serious social unrest," he added.

United Nations Security Council meets, amid Russia's invasion of Ukraine, at the United Nations Headquarters in Manhattan, New York City, New York, U.S., April 5, 2022. REUTERS/Andrew Kelly

(Reporting by Michelle Nichols; Editing by Doina Chiacu)

U.S. Ambassador to the United Nations Linda Thomas-Greenfield and United Nations Secretary General Antonio Guterres speak as they arrive for a United Nations Security Council meeting, amid Russia's invasion of Ukraine, at the United Nations Headquarters in Manhattan, New York City, New York, U.S., April 5, 2022. REUTERS/Andrew Kelly

Russian Ambassador to the United Nations Vassily Nebenzia addresses the United Nations Security Council during a meeting, amid Russia's invasion of Ukraine, at the United Nations Headquarters in Manhattan, New York City, New York, U.S., April 5, 2022. REUTERS/Andrew Kelly

Ukrainian Ambassador to the United Nations Sergiy Kyslytsya arrives for a United Nations Security Council meeting, amid Russia's invasion of Ukraine, at the United Nations Headquarters in Manhattan, New York City, New York, U.S., April 5, 2022. REUTERS/Andrew Kelly