The price of oil initially increased more than 4% when news of the US evacuation broke, in anticipation of regional insecurity potentially leading to supply problems. Around 2,500 US troops are based in Iraq, according to the defence department.

US embassies across the Middle East are preparing to send home non-essential staff and families amid rising tension in the region. President Donald Trump said US personnel were being moved out of the Middle East because "it could be a dangerous place.

The move comes after the Iranian defense minister warned that Tehran would target U.S. bases in the area if tensions escalated.