Saint-Jean-de-Luz, France (CNN) President Donald Trump skipped a session devoted to climate change at the G7 summit here, a snub aides wrote off as a scheduling conflict but nonetheless reflects Trump's isolation on the issue.

As other leaders were taking their seats around a large round table, the chair reserved for Trump sat empty. The summit's host, French President Emmanuel Macron, gaveled the meeting to order anyway and launched into an explanation of a wrist watch made from recycled plastic.

Later, the White House said Trump's schedule prevented his attendance.

"The President had scheduled meetings and bilaterals with Germany and India, so a senior member of the Administration attended in his stead," press secretary Stephanie Grisham said.

But the leaders of both those countries -- German Chancellor Angela Merkel and Indian Prime Minister Narendra Modi -- were both seen attending, at least for the start of the session.

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