The US military has drawn up plans to hit Iranian energy infrastructure and nuclear sites with the so-called ‘Mother of all Bombs’ should Donald Trump give the green light, according to a report.

US officials familiar with the designs told CNN that the military was preparing to use its GBU-43/B Massive Ordnance Air Blast Bomb (MOAB) in a significant escalation of the conflict with Iran.

The MOAB is the largest non-nuclear weapon in the US arsenal, although the outlet reported doubts around how effective its use would be towards achieving the president’s goals.

The conflict in the Middle East, which began with US-Israeli attacks in February, has slowed to an impasse since the collapse of a June interim agreement to end the war.

President Trump had sought to ensure Iran would never gain access to nuclear weapons, but eight months on Iran has unprecedented influence over the vital Strait of Hormuz, and Trump’s popularity is waning at home ahead of the November midterm elections.

According to CNN, Trump and his advisors have spent months discussing options for a ‘definitive’ act to end the war, noting the growing unpopularity among US voters.

One unnamed source told the outlet that Trump has ordered the military to develop additional strike packages that include “a lot of energy infrastructure” and could foreseeably use a MOAB.

Another source said the plans include striking nuclear sites including the so-called Pickaxe Mountain, which Trump has repeatedly threatened to target in recent weeks.

The United States last year carried out a blitz of strikes on the underground nuclear facilities at Fordow, Natanz and Isfahan, using GBU-57 Massive Ordnance Penetrator (MOP) “bunker-buster” bombs to penetrate through metres of rock and soil.

Seven B-2 bombers dropped a total of 14 of the 14,000kg bombs on Fordow and Natanz, while Isfahan was hit with more than two dozen Tomahawk missiles fired from a US submarine.

Read More: Trump threatens to drop ‘the mother of all bombs’ on Iran in major escalation