President Donald Trump says he will again withdraw the United States, a top carbon polluting nation, from the landmark Paris climate agreement, dealing a blow to worldwide efforts to combat global warming and once again distancing the U.

Trump’s day-one actions on energy come as climate change-fueled fires ravage Southern California, following the globe’s hottest year on record.

WASHINGTON (Reuters) - President Donald Trump will order the U.S. to withdraw from the Paris climate agreement, the White House said on Monday, once again placing the world's top historic emitter of greenhouse gas emissions outside of the global pact aimed at pushing nations to tackle climate change through domestic actions.

America is the world's second-largest greenhouse gas polluter - and it will no longer be part of global efforts to limit climate change through the landmark Paris Agreement.

Under the U.N. rules at the time, the U.S. withdrawal took three years to take effect, allowing former President Joe Biden to swiftly reinstate American participation in the accords. This time, however, the U.S. could completely quit the Paris Agreement in just one year.

The UN climate chief said Monday the "door remains open" to the landmark Paris accord after US President Donald Trump vowed to pull his country out of it for the second time.

President Donald Trump is ordering the US to withdraw from the landmark Paris Agreement, launching another retreat in the fight against climate change by the world’s wealthiest nation.

Quitting the Paris Agreement triggers a cascade of real-world impacts and signals the beginning of an aggressive agenda to undo U.S. climate policy.

The United States would be one of only four countries outside the Paris Agreement, which is designed to reduce global greenhouse gas emissions.

President Donald Trump will once again withdraw the United States from the Paris climate deal, the White House said on Monday, removing the world's biggest historic emitter from global efforts to fight climate change for the second time in a decade.