The announcement from the US president sparked fresh hopes among investors that the Strait of Hormuz transit route could be reopened. Brent crude oil fell below 83 US dollars (£61.73) a barrel on Monday, down nearly 6%. Oil prices have been volatile in recent weeks, swinging higher in response to renewed tensions in US-Israel's war with Iran, then drifting lower as leaders signal towards peace talks rekindling. Iran has repeatedly attacked vessels attempting to transit through the Strait of Hormuz without its authorisation as part of the conflict. About a fifth of the world's oil and gas flowed through the critical waterway before the war effectively cut off most transit routes.