The warning came as German Chancellor Angela Merkel has said this year’s G20 summit in Hamburg will focus on climate change.

Chancellor Angela Merkel: “The European Union stands fully behind its Paris commitment, and it will rapidly and decisively implement the agreement. Furthermore, since the decision by the United States of America to leave the Paris climate deal, we are more determined than ever to make it a success.”

The White House said President Trump will meet next week with Russian President Vladimir Putin on the sidelines of the G20.