The Kremlin confirmed on Tuesday that an oil-for-goods barter deal between Russia and Iran was being implemented and said all legal barriers had been removed to Moscow supplying S-300 missile systems to Tehran. Kremlin spokesman Dmitry Peskov declined to give any details of the barter deal. But asked whether a senior Foreign Ministry official was correct when he said on Monday that the exchange had begun, Peskov told reporters: 'Absolutely. Of course.' Peskov also said no legal barriers remained to supplying the advanced Russian air defence system S-300 to Iran after President Vladimir Putin signed a decree on Monday lifting a ban on such deliveries.