The source, speaking on condition of anonymity, said Mr Trump was working out the terms of the planned withdrawal with US Environmental Protection Agency Administrator Scott Pruitt, an oil industry ally and climate change doubter. Trump had tweeted he would make a decision on the Paris climate change deal this week. Credit:AP Mr Trump had refused to endorse the landmark climate change accord at a summit of the G7 group of wealthy nations on Saturday, saying he needed more time to decide. He then tweeted that he would make an announcement this week. Under the pact, virtually every nation voluntarily committed to combat climate change with steps aimed at curbing global emissions of "greenhouse" gases such as carbon dioxide generated from burning of fossil fuels that scientists blame for a warming planet, sea level rise, droughts and more frequent violent storms. It was the first legally-binding global climate deal.

The decision will put the United States in league with Syria and Nicaragua as the world's only non-participants in the Paris Climate Agreement. It could have sweeping implications for the deal, which relies heavily on the commitment of big polluter nations to reduce emissions of gases scientists blame for sea level rise, droughts and more frequent violent storms. Under the pact, the United States committed to reducing its emissions by 26 to 28 per cent from 2005 levels by 2025. Ivanka Trump reportedly lobbied her father to remain in the climate deal. Credit:AP Mr Trump has said the accord would cost the US economy trillions of dollars without tangible benefit. "The president will make an announcement when he's made a final decision," one senior official said. Mr Trump has changed his mind on large decisions before, even after previously signalling a move in the opposite direction.

News outlet Axios, which first reported the withdrawal, said details of the pullout are being worked out by a team that includes Mr Pruitt. The choice is between a formal withdrawal that could take three years or leaving the UN treaty that the accord is based on, which would be quicker but more extreme, according to the Axios report. CBS News confirmed the report, saying Trump had told allies he would be pulling out of the deal. Fox News also cited an unidentified source confirming the withdrawal. A US decision to withdraw from the accord could further alienate American allies in Europe already wary of Mr Trump and call into question US leadership and trustworthiness on one of the world's leading issues. A pullout also would be one more step by the Republican president to erase the legacy of his predecessor, Democrat Barack Obama, who helped broker the accord and praised it during a trip to Europe this month. The decision to withdraw from the climate accord was influenced by a letter from 22 Republican US senators, including Majority Leader Mitch McConnell, calling for an exit, Axios reported. The United States is the world's second-biggest carbon dioxide emitter behind China.

Supporters of the climate pact are concerned that a US exit could lead other nations to weaken their commitments or also withdraw, softening an accord that scientists have said is critical to avoiding the worst impacts of climate change. Canada, the European Union, and China have said they will honour their commitments to the pact even if the United States withdraws. A source told Reuters that India had also indicated it would stick by the deal. Environmental groups criticised the planned withdrawal. The Sierra Club said a US withdrawal from the Paris deal would be a "historic mistake." Friends of the Earth said it would make America the world's "foremost climate villain." Mr Trump had vowed during his campaign to "cancel" the Paris deal within 100 days of becoming president, as part of an effort to bolster US oil and coal industries. That promise helped rally supporters sharing his skepticism of global efforts to police US carbon emissions. After taking office, however, Mr Trump faced pressure to stay in the deal from investors, international powers and business leaders, including some in the coal industry. He also had to navigate a split among his advisers on the issue.

Trump aides including Steve Bannon, Stephen Miller, lawyer Don McGahn and Peter Navarro, along with Mr Pruitt, argued hard for leaving the accord. They said the deal would require the US government to regulate greenhouse gas emissions, which would hurt business. Mr Trump's administration has already begun the process of killing Obama-era climate regulations. The "stay-in" camp, which included Mr Trump's daughter Ivanka, chief economic adviser Gary Cohn, and Energy Secretary Rick Perry, had argued the United States could reduce its voluntary emission-cuts targets while still keeping a voice within the accord. Oil majors Shell and Exxon Mobil have also supported the Paris pact, along with a number of Republican lawmakers. Several big coal companies, including Cloud Peak Energy, had publicly urged Mr Trump to stay in the deal as a way to help protect the industry's mining interests overseas, though others asked Mr Trump to exit the accord to help ease regulatory pressures on domestic miners. Mr Trump has repeatedly expressed doubts about climate change, at times calling it a hoax designed to weaken US industry. An overwhelming majority of scientists, however, say climate change is driven by human use of fossil fuels.

A US pullout would be disappointing but the European Union stands ready to take global leadership on the issue, European Commission Vice President Maros Sefcovic said in Brussels. "There is a much stronger expectation from our partners across the world, from Africa, Asia and China, that Europe should assume leadership in this effort and we are ready to do that," Mr Sefcovic added. Loading The European Union and China are working on a joint declaration reaffirming their commitment to climate and energy policy and the implementation of the Paris agreement, according to an EU official with knowledge of the plans. Reuters