Iran sued Russia’s state-run arms corporation Rosoboronexport in the international arbitration court in Geneva last April.
Ambassador Mahmoud-Reza Sajjadi said in an interview with the Russian Izvestia daily that Iran demanded $900 million in compensation over Russia’s failure to deliver the systems, but the court added another $3 billion to the compensation.
Sajjadi said he hoped Tehran and the Russian Federal Service for Military-Technical Cooperation would resume negotiations to resolve the issue.
Russia has been working hard to persuade Iran to withdraw its claim but Tehran has invariably refused.
The lawsuit was lodged six months after then-president Dmitry Medvedev signed a decree terminating the contract, in line with UN Security Council Resolution 1929, which bans supply to Iran of conventional weapons including missiles and missile systems, tanks, attack helicopters, warplanes and ships.
Tehran has insisted that the S-300 surface-to-air missile systems do not fall under the UN sanctions.