UNITED States President Donald Trump has ordered the withdrawal of the United States from dozens of international organisations, many of which are involved in tackling climate change and other global challenges.

Almost half of the 66 organisations affected are linked to the United Nations, including the UN Framework Convention on Climate Change (UNFCCC), the treaty that forms the foundation of international efforts to address global warming.

Also on the list are groups focused on development, gender equality and conflict resolution, which are areas the Trump administration has frequently criticised as promoting what it describes as ‘globalist’ or ‘woke’ priorities.

The White House said the decision was based on a determination that the organisations no longer aligned with US interests and instead promoted agendas it considered ineffective or hostile.

The move was formalised in a memorandum signed on Wednesday after an internal review. In a statement, the White House described the affected bodies as ‘a waste of taxpayer dollars.’

It said the withdrawals would end U.S. funding and participation in organisations that placed global priorities ahead of national ones, adding that many supported ‘radical climate policies, global governance and ideological programmes’ at odds with American sovereignty and economic strength.

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Beyond the UNFCCC, the U.S. is also exiting the Intergovernmental Panel on Climate Change (IPCC), the world’s leading authority on climate science responsible for compiling major assessments on rising global temperatures.

Sources within the IPCC told the BBC they were worried about how the decision could affect U.S. scientists contributing to the organisation’s next round of reports.

The administration has already prevented American researchers from attending a recent IPCC meeting in China.

Limits on travel or participation by US scientists could slow the release of upcoming IPCC assessments, including its mitigation report, which provides governments with guidance on reducing emissions.

Several non-UN bodies are also affected, including organisations that promote clean energy collaboration, democratic governance and international security. These include the International Solar Alliance, the International Institute for Democracy and Electoral Assistance, and the Global Counter-Terrorism Forum.

Trump has previously cut funding to multilateral institutions he opposes and has repeatedly dismissed the scientific consensus on human-caused climate change, once calling it a ‘hoax.’

“This ‘climate change,’ it’s the greatest con job ever perpetrated on the world, in my opinion,” Trump said in September in New York.

Although a full withdrawal from the UNFCCC will take a year to complete, the US has in practice played little active role in the UN climate process for some time.

It is not yet clear whether the decision will face legal challenges in US courts, a step campaigners are now encouraging.

While the US Constitution allows presidents to enter treaties with the approval of two-thirds of the Senate, it is silent on the process for withdrawal, raising questions about whether a future administration could easily reverse the move.

The latest exits follow Trump’s decision last year to pull the US out of the Paris Climate Agreement for a second time and to skip sending a delegation to the COP30 climate summit in Brazil.

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The US has already withdrawn from other major international bodies, including the World Health Organization, the UN Human Rights Council and the UN cultural agency, UNESCO.

European leaders criticised the decision, warning it would undermine global cooperation. EU climate commissioner, Mr Wopke Hoekstra, said the UNFCCC is central to global climate action and described the US withdrawal as ‘regrettable and unfortunate.’ The EU’s vice-president for clean transition, Ms Teresa Ribera, said the move showed little regard for the environment, public health or human suffering.

The Union of Concerned Scientists, a US-based advocacy group, described the step as a ‘new low.’

Its senior Policy Director, Ms Rachel Cleetus, told AFP that the decision was further evidence that an administration she labelled ‘authoritarian’ and ‘anti-science’ was willing to sacrifice public wellbeing and weaken international cooperation.