UPDATE 6pm: British environmentalists accused Donald Trump of treating the international community with "utter contempt" after he refused to sign up to global action on climate change at an international summit.
The US President told leaders of the G7 countries that they would have to wait until next week for his decision on whether America would honour its undertakings under the Paris Agreement to limit global warming.
Under pressure from other G7 states - the UK, Germany, France, Italy, Canada and Japan - Mr Trump put his name to commitments to avoid trade protectionism and preserve a rules-based trade system.
But he refused to join the consensus on climate change, sending a tweet to say: "I will make my final decision on the Paris Accord next week!"
European leaders made little attempt to hide their frustration, with German Chancellor Angela Merkel describing discussions on climate change at the gathering in Sicily as "very unsatisfying".
EARLIER: President Donald Trump has he will make a final decision on whether the US will stay in the Paris climate agreement next week.
He made the surprise announcement on Twitter after resisting pressure from European leaders at the G7 summit in Sicily to commit to staying in the pact.
The president tweeted on Saturday: "I will make my final decision on the Paris Accord next week!"
Earlier on Saturday, the other six members of the G7 group of some of the world's wealthiest nations, voted to abide by the Paris climate agreement, according to a source familiar with the talks.
Mr Trump was cajoled for three days - first in Brussels at meetings of Nato and the European Union and then in Sicily - but will leave Italy without making clear where he stands.
Under the G7 agreement, the Trump administration will be given more time to consider whether it will remain committed to the 2015 Paris deal to rein in greenhouse gas emissions.
Backing out of the climate accord had been a central plank of Mr Trump's campaign and aides have been exploring whether they can adjust the framework of the deal even if they do not opt out entirely.
I will make my final decision on the Paris Accord next week!— Donald J. Trump (@realDonaldTrump) May 27, 2017
Other G7 nations leaned heavily on Mr Trump to stay in the climate deal, with German Chancellor Angela Merkel saying "we put forward very many arguments".
"His views are evolving, he came here to learn and get smarter," Gary Cohn, national economic council director, said on Friday of the president's thinking.
Mr Trump once proclaimed global warming a Chinese hoax.
The G7 comprises the US, Canada, France, Germany, Italy, Japan, and the UK.