Academy Award-winning actor Leonardo DiCaprio called on world leaders assembled at the United Nations to go beyond their commitments under the Paris Agreement on climate change, and push for “bold, unprecedented action.”

Representatives from more than 170 countries met on Earth Day to sign the Paris Agreement, setting a record for the most signatories to any international agreement in history on the first day it was open for signature.

The signing event, organized by U.N. Secretary-General Ban Ki-moon, is intended to galvanize additional actions and ensure that the agreement enters into force sooner than initially anticipated, by 2017 rather than the original date of 2020.