President Trump is likely to pull out of the Paris Climate Deal, according to his former adviser on the Environmental Protection Agency, Myron Ebell.

The action could come by executive order in a matter of days, reported the Independent, which would be his sixth since officially becoming president.

The Paris Climate Deal pledged to bring all nations together for the first time with the shared goal of combating climate change and adapting to its effects, and to assist developing countries in doing the same. So far 197 countries have signed on, including the United States.

While at a briefing in London, Ebell said Trump was intent on undoing Obama's policies that call for restrictions on greenhouse gases.

"I expect Donald Trump to be very assiduous in keeping his promises, despite all of the flack he is going to get from his opponents," Ebell said at the briefing. "He could do it by executive order tomorrow, or he could wait and do it as part of a larger package. There are multiple ways and I have no idea of the timing."

Ebell's comments come at a time when Trump is embroiled in ongoing tensions with the Prince of Whales regarding climate change. The president is scheduled to meet with Prince Charles when he visits Britain in June, but Trump's team is concerned that their contradicting views on the environment will make for an awkward encounter.

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The president's representatives have told UK officials that Charles should not push him on climate issues, reported the The Times of London, warning that Trump may "erupt" in response. The White House is said to have suggested that Prince William and Prince Harry meet with Trump instead.

Prince Charles has been a champion of environmental protection for more than 40 years, launching various sustainability projects, such as the Prince's Rainforest Project and the International Sustainability Unit.

In contrast, Trump has called climate change a "hoax" invented by the Chinese in order to damage the American manufacturing industry.

During his recent Senate hearing, Trump's new secretary of state, former ExxonMobil CEO Rex Tillerson, acknowledged that climate change does exist and acknowledged the benefits of remaining in the Paris deal.

"I think it's 190 countries have signed on," Tillerson said of the pact. "We're better served by being at that table than by leaving that table."

But according to Ebell, any effort made by Tillerson to keep the United States in the deal will be pointless.

"His mandate is pretty clear," Ebell said of Trump, who secured the presidency in the Electoral College after losing the popular vote to Hillary Clinton by nearly three million votes, "and he knows who he got it from. If Rex Tillerson disagrees with the president, who is going to win that debate?"

Since leaving Trump's transition team, Ebell has gone back to his role at the Competitive Enterprise Institute, an anti-regulation group who has received money from ExxonMobil in the past. "The environmental movement is, in my view, the greatest threat to freedom and prosperity in the modern world," Ebell also stated in London.

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Trump officials are primarily concerned with heavy media scrutiny if the success of his initial meeting with the Royal Family is thwarted by Prince Charles.

"Their paranoia of the media means that anything that goes slightly off-pitch will be hammered back home as him not getting a good reception from the future king of England and thousands of people protesting on the streets," a senior government source told The Times.

That said, it would be "a major breach of protocol" for Trump to try and exclude Charles from the meeting, a royal source told The Times. "We are very clear the prince will carry out his role in a state visit as always, and his views on climate change would not and should not affect his ability to do that."

The president's first UK visit is planned for June, but there's a chance it could be much later in the year. After UK Prime Minister Theresa May spoke to the Republican congressional leadership last week, Trump may be invited to speak at the Conservative Party conference in Manchester in October.

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