Under article 28 of the Paris Agreement, a Party may withdraw at any time after three years from the date on which the accord has entered into force for that Party. The withdrawal takes effect one year from the notification date. For the United States, the agreement entered into force on 4 November 2016. On 4 August, 2017 the United Nations Secretary-General announced he had received a notification from the USA expressing its intention to withdraw from the agreement as soon as it was eligible to do so. On 4 November 2020, the USA formally withdrew from the Paris Agreement.
