President Donald Trump has signed an executive order aimed at expanding offshore drilling, by opening up protected waters in the Atlantic, Pacific and Arctic Oceans.

The order is the latest part of Mr Trump's quest to undo former President Barack Obama's climate and environmental policies and instructs the Department of the Interior to review lease restrictions that stopped the oil and gas industry from setting up rigs in a large swath of ocean. The drilling restrictions, which were put into place last year by Mr Obama, were set to expire in 2022.

Once implemented, the order will open up millions of acres of federal waters to allow oil and gas exploration, leasing, and drilling. Trump, when signing, praised the vast reserves of natural resources that the United States has sitting untouched.

"But the federal government has kept 94 percent of these offshore areas closed for exploration and production, and when they say closed, they mean closed," Mr Trump said.

But Mr Trump's order isn't likely to have an immediate consequence for offshore drilling sites. It will likely take years to rewrite federal leasing plans and funding for drilling in places like the Arctic — where icy waters can impede drilling efforts — may hit snags if new drilling rigs aren't competitive against other established fuel extraction points.

Before the signing itself, activists expressed outrage saying that tapping those oil reserves would have catastrophic effects on efforts to curb climate change while the oil and gas industry cheered the prospect of expanded access to domestic energy resources, even though the price of oil is at a relatively low point.

"Opening new areas to offshore oil and gas drilling, including the Arctic, Atlantic, and the Pacific, risks locking us into decades of harmful pollution, devastating spills like the Deepwater Horizon tragedy, and a fossil fuel economy with no future. Scientific consensus is that the vast majority of known fossil fuel reserves – including the oil and gas off US coasts– must remain undeveloped if we are to avoid the worst effects of climate change," Diana Best, the senior climate and energy campaigner at Greenpeace, told the Independent in an email ahead of the signing.

"This executive order from Trump is just the latest in a series of rollbacks that most people in this country do not want, and only come at the behest of Trump’s inner circle of desperate fossil fuel executives," she continued. "Holing up at Mar-a-lago may protect Trump from an oil spill, but it will not protect him and his cabinet of one percenters from the millions of people in this country - from California to North Carolina - who will resist his disastrous policies.”

Erik Milito, the upstream director at the American Petroleum Institute said that allowing access to the oil reserves off US coasts is a key component of ensuring a successful long-term American energy policy.

"We’ve been advocating for expanded access to domestic energy resources for years," Mr Milito told the Hill. "When you want to pursue an effective, long-term energy strategy, it’s important to make sure that you’re creating opportunities through a predictable, long-term schedule so that the industry can determine whether we have the additional resources that can help fuel our economy."