Oil extended gains by around 2% on Wednesday as President Donald Trump reimposed a naval blockade on all Iranian ports and Iran's Islamic Revolutionary Guard Corps threatened to close "all other export corridors that benefit the U.S. and its allies".Brent futures LCOc1 climbed $1.71, or 2%, to $86.44 a barrel at 0806 GMT. West Texas Intermediate futures CLc1 gained $1.43, or 1.8%, to $80.