Birol said the world has never faced a disruption of energy supply on this scale.

European countries, as well as Japan, Australia, and others, will be affected, but developing nations are at the greatest risk, facing higher fuel and food prices and accelerated inflation.

IEA member countries agreed last month to release part of their strategic reserves, a process that has already begun, Birol noted.

The blockade comes in response to strikes by Israel and the US.

Iran has almost entirely halted traffic through the strait, which carries about 20 per cent of the world’s oil and gas, causing a surge in global energy prices.