The US State Department has officially informed the United Nations it will withdraw from the Paris Climate Agreement, but has left the door open to re-engaging if the terms improved for the United States.

The State Department said in a press release the United States would continue to participate in United Nations 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 the release.