The U.S. president is due to make his announcement at 2 p.m. ET.

Crude futures hovered close to multiyear highs on Tuesday, as investors awaited Trump's decision on the Iran nuclear accord.

President Donald Trump's eagerly anticipated announcement on the Iran nuclear deal could be the flashpoint for a "long-lasting" uptick in oil prices, according to Barclays analysts. Crude futures hovered close to multiyear highs on Tuesday, as investors awaited Trump's announcement at 2 p.m. ET. The prospect of the U.S. withdrawing from the landmark agreement to limit Iran's nuclear program, formerly known as the Joint Comprehensive Plan of Action, has ramped up energy market fears of an imminent supply shock. "The geopolitical consequences of a possible dismantling of the JCPOA would likely to play a larger and long-lasting role in pushing oil prices higher than short-term policy uncertainty," Michael Cohen, Barclays director of energy market research, said in a research note Monday.

Workers position a section of pipe during drilling operations at a gas well outside Corpus Christi. Patterson-UTI Energy is drilling the well for Decker Operating of Houston. Eddie Seal | Bloomberg | Getty Images

Trump is likely to either announce he will not be renewing a waiver on Iranian sanctions or reaffirm his firm opposition to the global pact, Barclays said. Regardless of Tuesday's announcement, Cohen predicted the current Iran nuclear deal would "not survive under President Trump." "And in the next couple of years, this more hawkish foreign policy could fuel already elevated tensions in the Middle East, specifically in Iraq, Syria, and Yemen, as the hostilities between Iran and Saudi Arabia escalate," Cohen added.

'No right' to renegotiate

Trump, a fervent critic of the accord, has long threatened to walk away from the landmark deal signed by Iran, the Obama administration, Russia, China, Britain, France, Germany and the European Union. Trump has complained the "insane" agreement does not restrict Iran's nuclear activities for long enough and fails to stop the country's development of ballistic missiles. In response, Iranian President Hassan Rouhani has said Trump has "no right" to renegotiate the deal and accused him of "maliciously violating" its conditions.

President Donald Trump gives a thumbs up while holding an umbrella in the rain as he arrives at Dallas Love Field aboard Air Force One to address the National Rifle Association Convention in Dallas, Texas U.S., May 4, 2018. Carlos Barria | Reuters

A dramatic uptick in crude futures over recent months has partly been driven by mounting expectations that the world's largest economy could soon pull out of the agreement. Ahead of the Trump administration's decision, Brent crude traded at around $75.38 on Tuesday morning, down 1 percent while U.S. West Texas Intermediate futures stood at $69.85, off around 1.2 percent.

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