PARIS • Former UN chiefs Kofi Annan and Ban Ki Moon have lashed out at the state of global leadership in the age of Donald Trump, warning a nuclear war could be triggered by accident.

"Honestly speaking, we are in a mess," Mr Annan told AFP ahead of yesterday's climate talks in Paris. "In the past, when we went through this sort of crisis, you had leaders who had the courage and the vision to want to take action, to understand that they needed to work with others."

Mr Annan was attending the One Planet Summit, which was called by French President Emmanuel Macron following United States President Trump's decision to abandon the global climate accord earlier this year.

Mr Annan urged leaders to cooperate better on fighting terrorism, migration and global warming.

"Today, leaders are going in the wrong direction," he said. "Leaders are withdrawing." He expressed particular concern over escalating tensions with North Korea, warning: "One miscalculation, one mistake and we are all victims".

"It may not be a deliberate decision to start a nuclear war," he said, adding that inflammatory rhetoric - without mentioning Mr Trump or North Korean leader Kim Jong Un by name - was not helping.

Mr Ban, who like Mr Annan spoke to AFP as part of The Elders group of senior statesmen and women, blasted Mr Trump's climate stance as "politically short-sighted and misguided". "The richest and most powerful country" in the world is disengaging from a historic deal that "even countries like Syria" have signed, Mr Ban said.

Meanwhile, former US secretary of state John Kerry blasted the absence of the American government at the Paris summit, calling it a "disgrace". The US federal government was represented by the second-highest diplomat in the American embassy in Paris, Mr Brent Hardt.

Mr Kerry and then President Barack Obama helped lead the efforts to clinch the Paris accord two years ago.

AGENCE FRANCE-PRESSE