UN Secretary General Antonio Guterres, who addressed the gathering by video message because of the pandemic, warned that "the only way to totally eliminate nuclear risk is to totally eliminate nuclear weapons".
United Nations Secretary-General Antonio Guterres on Thursday decried countries - without naming any - who rejected facts about the coronavirus pandemic and ignored guidance from the World Health Organization (WHO).
Guterres addressed a special session of the 193-member U.N. General Assembly on COVID-19, which emerged in the Chinese city of Wuhan late last year and spread globally, so far infecting nearly 65 million people and killing nearly 1.5 million.
Dozens of world leaders have submitted pre-recorded video statements for the two-day meeting.
"From the start, the World Health Organization provided factual information and scientific guidance that should have been the basis for a coordinated global response," Guterres said.
"Unfortunately, many of these recommendations were not followed. And in some situations, there was a rejection of facts and an ignoring of the guidance. And when countries go in their own direction, the virus goes in every direction," he said.
U.S. President Donald Trump cut funding to the WHO earlier this year and announced plans to quit the Geneva-based body over accusations it was a puppet of China, which the WHO denied. The U.S. withdrawal would have taken effect in July next year, but U.S. President-elect Joe Biden has said he will rescind the move.
"The pandemic underscores the importance of the World Health Organization, an institution that needs to be strengthened," said German Chancellor Angela Merkel.
Long-simmering tensions between the United States and China hit boiling point over the pandemic at the United Nations, where months of bickering between the superpowers has spotlighted Beijing's bid for greater multilateral influence in a challenge to Washington's traditional global influence.
China's Foreign Minister Wang Yi and U.S. Health and Human Services Secretary Alex Azar did not name any countries in their General Assembly statements, but both made veiled references.
"The world is braced for a second wave of infection - what lies ahead is a tenuous and uphill battle," said Wang. "Defeating the pandemic requires concerted efforts from all countries. The major ones in particular should play an exemplary role in promoting collaboration."
In a statement due to be broadcast, Azar cited a lack of "necessary information sharing," adding: "This dereliction of duty has been absolutely devastating for the entire globe." Washington has long asserted that a lack of transparency by Beijing worsened the global outbreak, which China denies.
"This is not a time to point fingers," U.N. General Assembly President Volkan Bozkir said. "The United Nations must lead on this."
Guterres is pushing for a COVID-19 vaccine to be made available to all and for rich countries to help developing countries combat and recover from the pandemic.
"France proposes a donation mechanism so that a portion of the first doses of vaccines available are used to vaccinate priority groups in developing countries," French President Emmanuel Macron told the General Assembly.
In his statement for broadcast, Britain's Health Secretary Matthew Hancock urged countries to lift export controls and tariffs on vital items needed to combat the virus, such as gloves and thermometers, adding: "We will put this into action ourselves from the 1 January."