Donald Trump's administration has officially told the United Nations that the US intends to pull out of the 2015 Paris climate agreement.
Last month the president announced that he planned to abandon the the landmark 'Paris Accord' global climate change deal in the face of domestic and international condemnation.
The historic global deal reached in the French capital in December 2015, saw nearly 200 countries agree to curb rising temperatures.
The Paris agreement went into effect on 4 November 2016, just days before Mr Trump was elected.
What key things does the agreement involve?
A pledge for countries to take action to limit temperature rises to "well below" 2C above pre-industrial levels
To pursue efforts to limit any increase 1.5C
A five-year review of climate action plans
Finance for poorer countries to develop along a low-carbon path and to cope with the impacts of climate change
A goal for greenhouse gases to peak as soon as possible and be rapidly reduced
Why does Donald Trump want to pull out of the deal?
President Trump's predecessor Barack Obama signed up to the deal without ratification by the US Senate.
Mr Trump, who has described climate change as a hoax by the Chinese to hurt US manufacturing, pledged to abandon the deal during the US presidential race.
He has also promised to boost fossil fuel production at home.
What is the mechanism for withdrawing?
The notification to the UN does not formally start the process of the US getting out of the voluntary agreement, but it sends a "strong message" to the world, the US State Department said.
A country can serve notice it is quitting the deal three years after it came into force, and it then takes another year to leave.
It would also be possible for the US not to formally leave but simply refuse to meet its commitments, which are voluntary for countries.
The State Department says it can officially start withdrawing as soon as November 2019.