Tehran previously has refrained from providing even a rough estimate of its reserves since the UN slapped a fourth round of sanctions of the country this summer.

The head of Iran's central bank, Mahmoud Bahmani, also is quoted by state TV as saying Tehran has increased its foreign reserves by billions of dollars by importing hundreds of tons of gold now worth twice what it was bought at.

Iran is under four sets of UN sanctions over its refusal to halt key parts of its nuclear program.