The US state department has issued its first written statement that it will withdraw from the 2015 Paris climate agreement, but left the door open to re-engaging if the terms improved for the United States.

But in a document given to the United Nations, the state department said Washington would continue to participate in climate meetings during the withdrawl process, which is expected to take at least three years.

Trump administration starts process of withdrawing from Paris climate accord https://t.co/hSXNwVtKBtpic.twitter.com/wKEnEXhjCr — Bloomberg (@business) August 4, 2017

“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 the release.

Donald Trump announced his decision to withdraw from the Paris deal in June, a move that caused international condemnation. He said the deal would have cost America trillions of dollars and killed millions of American jobs.

Schwarzenegger launches project to help lawmakers challenge Trump on climate change https://t.co/9xkz5ngJrrpic.twitter.com/FT3CApzw9u — The Hill (@thehill) August 4, 2017

Climate change is one of the biggest global threats to human health of the 21st century.

By the end of the century, it’s estimated two out of three people living in Europe will be affected by heat waves, coastal flooding and other weather-related disasters.