UN Secretary-General António Guterres addressed the UN General Assembly Monday in its first emergency meeting since 1982, urging that the fighting in Ukraine must stop.
"The fighting in Ukraine must stop," warned Mr Guterres, after the session began with a minute of silence for the victims of the conflict.
"Enough is enough. Soldiers need to move back to their barracks. Leaders need to move to peace. Civilians must be protected," he pleaded.
The top UN leader also called Russian putting nuclear defenses on alert "a chilling development."
"Yesterday, Russian nuclear forces were put on high alert. This is a chilling development. The mere idea of a nuclear conflict is simply inconceivable. Nothing can justify the use of nuclear weapons," he said.
The 193 members of the UN General Assembly held an extraordinary debate on a resolution condemning Moscow's "aggression" in Ukraine.
Mr. Guterres said the escalating violence, resulting in civilian deaths, including children, was totally unacceptable.
He asserted that the sovereignty, independence and territorial integrity of Ukraine, within its internationally recognised borders, must be respected.
Mr. Guterres also appointed Amin Awad as the UN Crisis Coordinator for Ukraine, who liaise with the government and all relevant actors on the ground — supported by the Resident and Humanitarian Coordinator and the UN Country Team.
The world is facing what is a tragedy for Ukraine, he added, but also a major regional crisis with potentially disastrous implications for all.
Mr. Guterres further underlined the UN's commitment to Ukraine, reminding that last week he had allocated $20 million from a UN humanitarian fund to support emergency operations, in addition to appointing a Crisis Coordinator for the country.
"At the same time, we are bringing together partners, in and outside the country – and surging personnel into the country," he continued.
The UN will also launch two coordinated emergency appeals for Ukraine and the region on Tuesday.
One will address escalating humanitarian needs inside the country, including rising internal displacement, while the other will respond to the needs of people who have fled elsewhere.
Assembly President Abdulla Shahid underscored that the military offensive launched by Russia five days ago was a violation of the integrity and sovereignty of Ukraine.
The assembly session came three days after an attempt to condemn and stop Russia's attack ran into a Russian veto in the Security Council.
The assembly will give all U.N. members an opportunity to speak about the war. More than 110 signed up to do so, with speeches to continue Tuesday. The assembly, which allows no vetoes, is expected to vote later in the week on a resolution coordinated by European Union envoys, working with Ukraine.