The United States has officially informed the United Nations it will withdraw from the Paris Climate Agreement, but left the door open to re-engaging if the terms improved.
The State Department said the US would continue to participate in UN climate change meetings during the withdrawal process, which is expected to take at least three years.
"The United States supports a balanced approach to climate policy that lowers emissions while promoting economic growth and ensuring energy security," the department said in a release on Saturday (NZT).
President Donald Trump announced his decision to withdraw from the Paris deal in June, saying the accord would have cost America trillions of dollars, killed jobs, and hindered the oil, gas, coal and manufacturing industries.
But he also said he would be open to renegotiating the deal, which was agreed on by nearly 200 nations over the course of years - drawing ridicule from world and business leaders who said that would be impossible.
During a visit last month to Paris to meet French President Emmanuel Macron, Trump told reporters, "Something could happen with respect to the Paris accords, let's see what happens."
"As the President indicated in his June announcement he is open to re-engaging in the Paris Agreement if the United States can identify terms that are more favourable to it, its businesses, its workers, its people, and its taxpayers," the State Department said in its press release.
The United States, under former President Barack Obama, had pledged as part of the Paris accord to cut US greenhouse gas emissions by as much as 28 percent from 2005 levels by 2025 to help slow global warming.
The earliest date for the United States to completely withdraw from the agreement is November 4, 2020, around the time of the next US presidential election.