Iran’s currency has fallen in recent days to a fresh record low, in a sign the US’s naval blockade is squeezing the Islamic Republic’s economy.

The rial depreciated to 1.8 million versus the dollar on Wednesday, according to Bonbast.com, a website that tracks its value on the black market. It’s down roughly 12% this week as the blockade on Iranian ports makes it harder for Tehran to keep exporting oil.