"This agreement gives foreign bureaucrats control over how much energy we use on our land, in our country", he said at a North Dakota rally where he outlined his energy policy.
The 2015 Paris Agreement, from which Donald Trump is considering withdrawing the United States, was the first pact to commit all nations to limiting global warming caused by emissions from burning coal, oil and gas.
"We therefore reaffirm our strongest commitment to swiftly implement the Paris Agreement, including its climate finance goals and we encourage all our partners to speed up their action to combat climate change".
"I'm hearing from a lot of people, both ways", Trump said as he met with Vietnamese Prime Minister Nguyen Xuan Phuc.
"When the President has a decision he will make that announcement and he will make it clear what the basis of that is".
The real question, however, is whether other countries would also proceed to weaken their commitments - or if they would stay the course and shun the U.S. The decision to leave the agreement is a message to the world: We'll take the lead on contributing to the problem, but not fixing it.
Trump's daughter and senior adviser, Ivanka, has worked to ensure her father heard pro-Paris voices over the last several months, and has continued to press for a decision short of a full withdrawal.
The president could also announce that he will begin formally pulling out of the accord outright - a process that would take three-and-a-half years under the standard cooling-off period for new worldwide treaties.
Trump's decision marked "a sad day for the global community", said Miguel Arias Canete, climate action commissioner for the European Union.
"But even if the government decides to leave the Paris agreement, it's very important for USA society as a whole - the cities, the states, the companies, the businesses - to remain engaged", he said.
Major U.S. allies, business leaders and even the Pope had urged the U.S.to remain in the deal. Members agreed to reduce carbon emissions and to keep global warming to below 2 degrees Celsius, starting no later than 2020.
Ivanka Trump and her allies, including Secretary of State Rex Tillerson and Trump's chief economist Gary Cohn, have pressed Trump to alter the U.S. commitments to the Paris agreement without fully pulling out of the accord. He's also a former senior adviser and India counselor to the U.S. Special Envoy on Climate Change at the State Department.
The US is the second-largest emitter of greenhouse gases in the world, right behind China. The Washington Post, and many other outlets, have already reported that Trump is leaning toward exiting the deal, while cautioning that he could still change his mind.
UN Secretary General Antonio Guterres has weighed in, arguing on Tuesday that the United States should not leave the Paris Agreement.
The Paris Agreement was in part brokered by Obama and was seen as a major breakthrough after the previous accord, the Kyoto protocol, failed to include the USA and China, the world's two biggest polluters.
The UNFCCC has almost universal membership and provides the underlying framework for global cooperation to combat climate change.