Donald Trump is poised to pull out of the Paris climate agreement, according to senior officials quoted in US media.
The US president vowed to back out of the pact, signed by nearly 200 countries, which aims to cut carbon emissions.
Christian humanitarian charities rushed to warn against the move after Trump tweeted he would announce his decision in the coming days.
Christian Aid's climate lead Mohamed Adow described the 2015 agreement as the 'pinnacle' of efforts to combat the issue and warned the 'consequences of climate change are a real and present danger to America'.
But he added it was better the US is isolated outside the Agreement 'rather than pulling it apart from the inside'.
He said: 'The US must face the consequences of this decision and the international isolation it has brought upon itself.
'Angela Merkel was quite clear last week that America could no longer be relied upon as an international ally. Pulling out of the Paris Agreement does not make America great, it diminishes it in the eyes of the world.'
Christian environmentalist charity Arocha previously described Trump's vow to quit the climate deal as a 'nightmarish scenario'.
CEO Andy Atkins said it was 'critical' other countries strengthen their resolve to tackle carbon emissions.
'By far the best antidote to Donald Trump's chilling attitude is for other countries to strengthen their own resolve to tackle climate change and nature loss, and reap the benefits of going green even faster,' he said.
Responding to the reports, a top EU official said the decision was 'disappointing' but Europe would continue leading the fight on climate change.
'If they decide to pull out it would be disappointing but I really do not think this would change the course of mankind,' said European Commission Vice-President Maros Sefcovic.
'There is a much stronger expectation from our partners across the world from Africa, Asia and China that Europe should assume leadership in this effort and we are ready to do that.'
Andy Lester, conservation director at A Rocha, Britain's primary Christian conservation charity, said: 'I think our greatest disappointment is he has been treating it like a media hype story. He is playing with an issue that could significantly change the way the world works over the next 20 – 30 years. China and the European Union are firing ahead but America is struggling. If he does pull out it is a huge embarrassment for America and leaves the agreement in a far weaker place.'
