Trump is also meeting Ukrainian President Volodymyr Zelensky, British Prime Minister Andy Burnham and leaders from Saudi Arabia, the United Arab Emirates, Qatar, Kuwait, Bahrain and Oman.
Earlier, Guterres gave his farewell speech as UN secretary general, urging unnamed superpowers to recognise “that their power isn’t so super”.
“The fault lines in our world are widening,” Guterres said, citing geopolitical rivalries, wars, climate change and artificial intelligence.
By contrast, Trump criticised international institutions, accusing the UN of a “far-left agenda of globalist bureaucrats who nobody ever elected”.
The US president instead emphasised national sovereignty and “unmatched” American military power.
“There is no global government,” he said.
He also warned that the US would not allow threats to establish themselves anywhere in the Western hemisphere.
“If necessary, we will use our unmatched military might to secure the vital national interests of the United States,” he said.
Trump accused Cuba’s communist government of cultivating ties to left-wing groups in the US, including the Communist Party USA, Antifa and the Democratic Socialists of America.
The Cuban delegation also appeared to walk out of the assembly chamber as Trump turned his sights on them, referring to the island as a “failed state”.