“We’ve obviously got a discussion going on about our policy in this regard,” Mattis said. “I was sitting in on some of the discussions in Brussels, by the way, where climate change came up, and the president was open. He was curious about why others were in the position they were in – his counterparts in other nations – and I’m quite certain the president is wide open on this issue as he takes in the pros and cons of that accord.”

Mattis also said the U.S. position on climate change is outside his purview as Secretary of Defense.

“Frankly, it’s not inside my portfolio, that aspect. Obviously we deal with the aspects of a warming climate in the Department of Defense, and to us, that’s just another one of many factors we deal with which we call the physical environment.”