Iran's chief banker said the U.S. dollar will be gradually eliminated from Iranian-Russian economic transactions, the official news agency IRNA reported on Thursday.

The trade volume between Iran and Russia stood at 4 billion U.S. dollars, which can be conducted through the Iranian currency rial and the Russian ruble, said Governor of the Central Bank of Iran (CBI) Ali Salehabadi in a televised interview.

The two countries have exchanged a memorandum of understanding to use their national currencies in small-scale trade transactions, he added.

In a Tuesday meeting with Russian President Vladimir Putin, Iran's Supreme Leader Ayatollah Ali Khamenei called for the gradual abandonment of the dollar in bilateral exchanges. Iran also launched the rial-ruble trading in its foreign exchange market on the same day.

Both Iran and Russia are under U.S.-led Western sanctions.