Russia said Wednesday it would maintain arms sales to Middle East ally Syria despite US pressure because the United Nations had failed to impose sanctions against President Bashar al-Assad's regime. The comments from the head of Russia's state weapons exporter came just days after US Secretary of State Hillary Clinton direct challenged Moscow to "get on the right side of history" and end supplies stretching back to Soviet times. Rosoboronexport director Anatoly Isaikin said his organisation was under contract to provide Syria with arms for as long as such sales remained legal under international law. "While no sanctions are announced, while there are no orders or directions from the government, we are obliged to fulfil our contractual obligations, which we are now doing," Isaikin told reporters. Speaking at the MAKS international airshow at Zhukovsky outside Moscow, he said that Russia was now in the process of sending jet trainers and weaponry to the violence-wrecked country. "We have been supplying and are supplying Yak-130 planes ... and military hardware." Russia also signed a 2007 deal to provide Syria with anti-ship cruise missiles that its arch-rival Israel fears may fall into the hands of Hezbollah militants in neighbouring Lebanon. In an interview with CBS News, Clinton said bluntly that countries such as China and India should impose energy sanctions on Syria while Russia needed to stop selling weapons to Assad. "We want to see Russia cease selling arms to the Assad regime," Clinton said. Moscow has already lost billions of dollars from the Middle Eastern unrest after it ceased selling weapons to Libya to comply with international sanctions against Moamer Kadhafi's regime, Isaikin said. Losses from broken-off contracts and contracts that were to have been signed with Libya "amount to around $4 billion," he said. The total value of arms that Russia supplied abroad in the first half of this year was $5.9 billion, he added. Russia has kept close ties with Syria for nearly five decades and remains one of its most important arms suppliers, keeping criticism of Assad's current actions to a minimum. Moscow has stressed that it remains firmly opposed to foreign interference in Syria and believes Damascus could find a political solution to its crisis, while recently urging Assad to to engage in honest negotiations. Russia repeated this nuanced approach against this month at the UN Security Council, where it backed a statement condemning "the widespread violations of human rights" in Syria while refusing to support actual sanctions. The Kremlin wields veto power in the UN Security Council and has blocked previous Western-drafted resolutions on Syria to the irritation of other world powers.