UNITED NATIONS (AP) -- Secretary-General Antonio Guterres warned the U.N.'s first-ever virtual meeting of global leaders Tuesday that the world is facing an "epochal" health crisis, the biggest economic calamity and job losses since the Great Depression, threats to human rights and worries of a new Cold War between the U.S. and China.
In his grim state of the world speech to the U.N. General Assembly's annual high-level meeting, the U.N. chief said the coronavirus that "brought the world to its knees" was but "a dress rehearsal for the world of challenges to come."
He called for global unity, first and foremost to fight the pandemic, and sharply criticized populism and nationalism for failing to contain the virus and for often making things worse.
But the prerecorded speeches from world leaders at the opening of the six-day session reflected deep global divisions.
U.S. President Donald Trump clashed with the presidents of China and Iran. Russian leader Vladimir Putin urged an end to U.S. and European Union sanctions. South African President Cyril Ramaphosa, speaking on behalf of the African Union, said rich nations haven't been generous enough in helping developing nations combat COVID-19, which is setting back the continent's development.
Days after the pandemic shut down big parts of the world in March, Guterres called for a global cease-fire to tackle it. On Tuesday, he appealed for a 100-day push by the international community, led by the U.N. Security Council, "to make this a reality by the end of the year."
"There is only one winner of conflict during a pandemic: the virus itself," the secretary-general stressed.
Reiterating a warning he made to world leaders a year ago about rising U.S.-China rivalry, he said, "We are moving in a very dangerous direction."
"Our world cannot afford a future where the two largest economies split the globe in a great fracture -- each with its own trade and financial rules and internet and artificial intelligence capacities," Guterres said. "A technological and economic divide risks inevitably turning into a geostrategic and military divide. We must avoid this at all costs."
The rivalry between the two powers was in full display as Trump, in a very short virtual speech, urged the United Nations to hold Beijing "accountable" for failing to contain COVID-19, which originated in China and has killed 200,000 Americans and nearly 1 million around the world.
Soon after, China's ambassador rejected all accusations against Beijing as "totally baseless."
"At this moment, the world needs more solidarity and cooperation, and not a confrontation," U.N. Ambassador Zhang Jun, sitting in the General Assembly chamber, said before introducing President Xi Jinping's prerecorded speech. "We need to increase mutual confidence and trust, and not the spreading of political virus. China resolutely rejects the baseless accusation against China."
In his appeal for a global cease-fire, Guterres said ending wars in the Middle East and Africa is critical to defeating the coronavirus.
Guterres said armed movements from Cameroon to Colombia, the Philippines and beyond responded to his original appeal even if several cease-fires they announced didn't last. But there are reasons to be hopeful, he said, pointing to a new peace agreement in Sudan, the launch of Afghan peace negotiations, and cease-fires largely holding in Syria's Idlib province, Ukraine and elsewhere.
The U.N. chief delivered his speech in the vast General Assembly Hall, where only one mask-wearing diplomat from each of the U.N.'s 193 member nations was allowed, spread out in the chamber.
"In a world turned upside down, this General Assembly Hall is among the strangest sights of all," Guterres said. "The COVID-19 pandemic has changed our annual meeting beyond recognition. But it has made it more important than ever."
Brazil's President Jair Bolsonaro, whose country by tradition is the first speaker, trumpeted his focus on the economy in dealing with the pandemic, lambasting "segments of the Brazilian media" for "spreading panic" by encouraging stay-at-home orders and prioritizing public health over the economy.
Bolsonaro has downplayed the severity of the virus and has repeatedly said shutting down the economy would inflict worse hardship on the population. That's despite Brazil reporting the second-highest coronavirus death toll after the United States, with over 136,000 dead, according to statistics collected by Johns Hopkins University.
Turkish President Recep Tayyip Erdogan criticized the start of the pandemic "where countries were left on their own," stressing that "effective multilateralism requires effective multilateral institutions." He urged rapid implementation of "comprehensive and meaningful reforms, starting with the restructuring of the Security Council," the U.N.'s most powerful body with five veto-wielding members -- the U.S., China, Russia, Britain and France.
In a fiery speech, Iranian President Hassan Rouhani whose country is facing the worst COVID-19 crisis in the Middle East, lashed out at U.S. sanctions but declared that his country will not submit to U.S. pressure.
He said the United States can't impose negotiations or war on Iran, stressing that his country is "not a bargaining chip in U.S. elections and domestic policy." He used George Floyd's death in May under the knee of a police officer as a metaphor for Iran's "own experience" with the United States.
"We instantly recognize the feet kneeling on the neck as the feet of arrogance on the neck of independent nations," Rouhani said.
Tensions have run dangerously high this year, and Trump signed an executive order this week to enforce all U.N. sanctions on Iran because it's not complying with a 2015 nuclear deal with world powers -- a move that most of the world rejects as illegal.
The General Assembly's annual meetings traditionally serve as a platform for countries to tout accomplishments, seek support, stoke rivalries and express views on global priorities.
This year, the platform is online, and there is a pressing new priority in the pandemic that has killed over 960,000 people worldwide.