United States (US) forces in the Middle East have prepared for new military operations against Iran that could begin within 96 hours of President of US Donald Trump issuing an order, as American officials develop plans for strikes on Iranian energy infrastructure, military sites and nuclear facilities.

Two US officials told an international media outlet that American forces already deployed in the region have the capacity to carry out the potential operations. The planned campaign will likely extend beyond limited strikes on Iranian radars, missile launchers and other military assets that Iran can quickly rebuild.

“It will be a big effort,” one of the officials told the outlet.

Current and former US officials familiar with military planning discussions believe Trump could authorise the operation before the end of the year, with the period after the US midterm elections considered the likeliest timeframe.

However, officials said that Trump has yet to make a final decision and has previously backed away from actions he appeared ready to approve.

An October 23 memo from Director of National Intelligence Jay Clayton to Secretary of State Marco Rubio said that US intelligence had found that Iran had stepped up efforts to target American personnel.

The memo stated that Iran’s plotting efforts “have reached advanced stages in both the Middle East and certain other countries.”

The perceived threat has prompted the US to prepare further reductions in diplomatic staffing across the Middle East. The US Embassy in Riyadh, Saudi Arabia, remains the only American diplomatic facility in the region under an ordered departure directive.

The US has also cancelled the planned deployment of non-essential military personnel who were due to arrive in the region as part of the next troop rotation.