The FTSE 100 closed lower on Wednesday, held back by falls for drugs firms GSK and AstraZeneca , while oil surged amid reports that the US is eyeing a longer blockade of the Strait of Hormuz. The FTSE 100 closed down 119.68 points, 1.2%, at 10,213.11. The FTSE 250 ended down 198.55 points, 0.9%, at 22,200.87, but the AIM All-Share rose 1.53 points, 0.2%, at 788.43. A White House official said US President Donald Trump was eyeing an Iran blockade lasting months if needed as the crisis in the Middle East showed no signs of easing, AFP reported on Wednesday. AFP said oil executives were told, in a meeting with Mr Trump held on Tuesday, that the US could extend its naval blockade of Iran for months more. US press reports have suggested Mr Trump has already decided to reject Iran’s latest proposed deal to reopen the Strait of Hormuz. According to the Wall Street Journal, he intends to pursue the blockade of Iranian ports until Tehran is forced to dismantle its nuclear programme.…