A portrait of Syrian regime president Bashar al-Assad has been printed on a new 2,000-pound banknote in Syria for the first time, a sign of the dictator's increasing confidence in the country's devastating war.

The new note is equivalent to around $4 at current exchange rates and went into circulation on Sunday.

Central bank governor Duraid Durgham said the 2000-pound note was one of several new notes printed years ago but the decision to circulate it was delayed to the "war and exchange rate fluctuations," Reuters reported.

The decision to put the new note into circulation was based on wear and tear of existing notes, Durgham said, and will be put into circulation "in Damascus and a number of the provinces".

Since the conflict in Syria began in 2011, the currency has plunged from 47 pounds to the dollar in 2010 to 500 pounds to the dollar at present.

The highest denomination of Syrian banknote was previously 1,000 pounds and featured Assad's father, long-time dictator Hafez al-Assad, who appeared on coins and an older version of the 1,000 pound note.

The decision to feature Assad's portrait on a brand new banknote appears to be a sign of the regime president's increasing confidence following military gains made in the country in recent months.

Backed by Russia, and Hizballah, the regime has steadily regained ground across the country, and in May, Russia, Turkey and Iran agreed to establish four "de-escalation zones' during peace talks in the Kazakh capital Astana.

Such gains have come at a devastating cost for citizens, however, with the regime accused of a "starve and siege" strategy in besieged opposition-held areas, together with accusations of chemical attacks, mass executions, and torture.

The Syrian conflict began when the Baath regime, in power since 1963 and led by Hafez's son Bashar al-Assad, responded with military force to peaceful protests demanding democratic reforms during the Arab Spring wave of uprisings, triggering an armed rebellion fuelled by mass defections from the Syrian army.

According to independent monitors, hundreds of thousands of civilians have been killed in the war, mostly by the regime and its powerful allies, and millions have been displaced both inside and outside of Syria.