Washington DC - The US will not send any top officials to the COP30 climate talks in Brazil later this month, a White House official said Saturday, as President Donald Trump instead works to boost fossil fuels.

Trump, who withdrew from the Paris climate agreement for a second time upon his return to the White House in January, had not been expected to attend a leaders' summit ahead of the annual UN climate conference in Belem.

But it now appears he will not dispatch any top negotiators to the talks, to be held from November 10-21, either.

"The US is not sending any high level representatives to COP30," a White House official said on condition of anonymity.

"The president is directly engaging with leaders around the world on energy issues, which you can see from the historic trade deals and peace deals that all have a significant focus on energy partnerships."

Brazil said Friday that fewer than 60 world leaders have confirmed they will attend the climate summit on November 6-7 – held separately this year to ease accommodation pressures.

The leaders of France, Germany, the United Kingdom, the Netherlands, Norway, Colombia, Chile, Cape Verde, and Liberia will attend, their governments have confirmed to AFP.

China has said Vice Premier Ding Xuexiang will represent President Xi Jinping.

While Trump also exited the Paris deal in his first term, his administration has gone further this time, exerting its clout to boost fossil fuels globally.

This includes, for example, threatening countries with retaliatory measures if they agreed to a carbon pricing system by the UN's International Maritime Organization, effectively curtailing its implementation.

Climate advocates fear the administration could seek to withdraw from the UN Framework Convention on Climate Change – the treaty that underpins the Paris Agreement.

Doing so could prevent future administrations from re-entering the deal, but it is not clear if the executive branch has the legal authority to undo a Senate-ratified treaty.

While Trump's administration appears to be ignoring the summit, more than 100 state and local US leaders – including governors and mayors – are still expected to join the talks.

"We are showing up in force," Gina McCarthy, co-chair of the America Is All In coalition, told reporters on a call Thursday.

McCarthy formerly served as the head of the Environmental Protection Agency under former President Barack Obama and as a climate advisor to Trump's predecessor Joe Biden.

She said the group heading to Brazil represented "two-thirds of the US population and three quarters of the US GDP, and more than 50% of US emissions."

"We'll deliver on the promises we made to the American people and our international colleagues," she said. "Local leaders here have authority to act on their own behalf, to take climate action at home and abroad."

In all, 170 delegations are accredited for the main COP30 conference, taking place at a time of global political turmoil that many fear will overshadow the climate crisis.