Iran's currency hit a record low Monday as Washington prepared to announce new sanctions it said would be an "economic D-Day" and would add further pressure on an economy already battered by previous sanctions and a U.S. naval blockade.

The rial dropped to 2.02 million to the U.S. dollar as trading opened on informal currency markets. Iran's official Central Bank rate stood at around 1.5 million rial to the dollar, but the informal rate is what most Iranians pay.