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 says he will again withdraw the United States from the landmark Paris climate agreement

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.

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

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.

President Donald Trump is once again withdrawing the United States from the Paris climate accords, pulling the nation whose factories, cars and power plants contributed the most cumulative planet-heating pollution to the atmosphere out of the first global pact to slash carbon emissions enough to prevent the world’s average temperature from reaching dangerous new heights.