Bashar Al Assad’s regime has “surrendered Syrian sovereignty” by giving up large areas of territory to foreign powers, a leading US envoy said. In an attack on the regime that has allowed the country to suffer almost a decade of civil war that has killed more than 500,000 people, Joel Rayburn said Syria had once been “a player in the region but now it finds itself as a playground”. Mr Rayburn was speaking in a online seminar hosted by the Beirut Institute Summit e-Policy Circles. The seminar also heard that Russia and Iran’s intervention was in part motivated by creating instability to increase oil prices. Mr Rayburn, the US deputy assistant secretary for Levant affairs and special envoy for Syria, said Mr Al Assad had “traded away” sovereignty in exchange for tactical agreements that allowed him to keep the presidency. “They've lost the country, just given it away, but the mystery for me is why the loyalists of the Syrian government tolerate that," he said. "For almost 10 years now, the supporters of the Bashar Al Assad government have literally lost their sons and at the end of that sacrifice they find other regional powers negotiating over Syrian land.” Mr Rayburn condemned Hezbollah’s presence in the country, saying Mr Al Assad’s father and predecessor, Hafez, would never have tolerated it without explicit permission. “Now Hezbollah does whatever it wants and goes wherever it wants inside Syria and Assad says nothing,” he said. The former National Security Council member and retired army officer said Mr Al Assad was allowing Iran to “import thousands” of militant fighters and then gave them Syrian citizenship. “Why is Assad helping the Iranian regime to colonise Syria?” Mr Rayburn asked. “The simple fact is, Iran should not be controlling Syria.” He said the only way to resolve the conflict was by implementing UN Resolution 2254, which calls for a ceasefire and political settlement in Syria. Mr Rayburn was joined by another US official, James Jeffrey, who said while Mr Al Assad needed to be held accountable for his war crimes, it was up to the Syrian people “to have a say in who governs them, and who is held accountable”. Syria had also been turned “topsy-turvy” by the Iranian intervention, said Mr Jeffrey, the special presidential envoy for the Global Coalition to Counter ISIS. As Mr Rayburn commented on the State Department's sanctions imposed on 17 Syrian regime figures, Mr Jeffrey said that the US would be going after others. “Wherever you are in the world, supporting this criminal regime, we're coming after you, just stand by," Mr Jeffrey said. "We'll get to you. "The problem is, there is such a rich target list of Syrian officials who have done so much to deserve sanctions that were we're still working our way through them, but people need to be patient. "We're going to take you down sooner or later.”