The president signed an executive order that raises questions about the timing of his planned exit from the global climate deal.

President Donald Trump will order the U.S. to withdraw from the Paris climate agreement, the White House said on Monday, once again placing the world's top historic emitter of greenhouse gas emissions outside of the global pact aimed at pushing nations to tackle climate change through domestic actions.

Delta is the first major U.S. airline to say it will not rollback its climate targets after Trump withdrew the U.S. from the Paris Agreement.