As other leaders were taking their seats around a large round table, the chair reserved for Trump was empty. He was later asked by reporters whether he had attended the climate session, to which he replied: "We're having it in a little while." He did not appear to hear when he was told that the session had already taken place.
The White House said Trump's schedule prevented his attendance at the climate session, the US media reported. "The President had scheduled meetings and bilaterals with Germany and India, so a senior member of the administration attended in his stead," said Press Secretary Stephanie Grisham.
But Indian Prime Minister Narendra Modi and German Chancellor Angela Merkel were seen attending the climate session, at least at the start of the discussion.
After the session, French President Emmanuel Macron seemed to shrug off Trump's absence.
"He wasn't in the room, but his team was," Macron said at a news conference. He urged reporters not to read too much into Trump's decision to skip the session, insisting the US was aligned with the rest of the G7 on issues of biodiversity and combating fires in the Amazon rainforest.
Still, Macron acknowledged Trump's decision to withdraw from the Paris climate accord in 2017 a move that angered European nations, who remain part of the pact.
Macron said it was no longer his goal to convince Trump to return to the agreement.
In the lead-up to the G7, Trump's aides said he wasn't entirely interested in the climate portions of the summit, believing them "a waste of time" compared to discussion of the economy.
The French leader announced that the G7 had agreed to an immediate fund of at least $20 million to help Amazon countries fight wildfires and launch a long-term global initiative to protect the rainforest.
( With inputs from IANS )