The South Ossetian authorities use tolls levied on tunnel traffic as one of their main sources of revenue. The Georgian government – backed by the United States – has long called for the South Ossetian side of the tunnel to be placed under the control of international monitors, rather than by the South Ossetian secessionists and their Russian allies.[5] When the Russian authorities blocked the Kazbegi-Verkhni Lars customs checkpoint between June 2006 and March 2010, the Roki Tunnel was the only available road route from Russia to South Ossetia. The tunnel was also used as a supply route for the Russian troops during the 2008 South Ossetia War.[6]