He said he needed more time to decide if he can sanction the move to curb greenhouse gas emissions.
As he left the summit in Sicily he tweeted: “I will make my final decision on the Paris Accord next week!”
- Former US-EU envoy hails Donald Trump's 'aggressive' NATO speech
- Donald Trump brands Manchester terror attack 'barbaric'
I will make my final decision on the Paris Accord next week!
He had rebuffed attempts by the six other members, including Britain, to join them in supporting the agreement.
They had tried to cajole Trump over three days, first in Brussels at meetings of Nato and the European Union, then at the meeting of the leading industrialised nations in Taormina, Italy.
Donald Trump said he needed more time to decide if he can sanction the move to curb emissions
But under pressure the President, who has previously called global warming a hoax, backed a pledge to fight protectionism and commit to a rules-based international trade system.
The defiance followed his typically brash behaviour in which he told off other allies for not paying more for their own defence.
World leaders gather at G7 summit 2017 Fri, May 26, 2017
Donald Trump will face Theresa May and world leaders at the G7 summit in Sicily
Play slideshow EPA 1 of 8
G7 Summit in Taormina
Get Quotes on Home Insurance
Donald Trump tweeted as he left the summit
Germany’s Chancellor Angela Merkel said: “The entire discussion about climate was very difficult, if not to say very dissatisfying.
“There are no indications whether the United States will stay in the Paris Agreement or not.”
Earlier this week he called Germany “very bad” on trade because of its surplus with the United States.