London: The man who wrote the Trump administration's environment action plan says the environmental movement is "the greatest threat to freedom and prosperity in the modern world" and said the United States was about to change course on climate policy, including withdrawal from the Paris agreement.

Myron Ebell, who led the Environmental Protection Agency transition for the new administration, said he gave the president three pathways for withdrawing from the 2015 Paris agreement on greenhouse gas emissions, at least one of which could be done "right now".

President Donald Trump has pledged to withdraw from the Paris climate agreement. Credit:Bloomberg

He also said the president had been clear he wanted to abolish the EPA - though it might survive as a channel for pollution clean-up grants to states.

And he hinted at an end to emission standards for US vehicles, through abolishing the EPA's 'endangerment finding', which had given it powers to protect the public from the health threat posed by greenhouse gases.