Bulgaria has denied its airspace to Russian aid flights to Syria, Reuters reports on Tuesday citing the Bulgarian foreign ministry's spokeswoman. "The Bulgarian foreign ministry has refused flights over Bulgaria of Russian military transport planes en route to Syria," the spokeswoman told Reuters. On Saturday, the US embassy appealed to Athens with a request to prohibit the flights of Russian aircraft providing aid to Syria, however, Greece refused to do so, a source told RIA Novosti. First Deputy Head of the International Committee of the Russian Federation Council Vladimir Jabbarov said Monday that Russia may use new flight aid routes to Syria if Greece closes its airspace to Russian aircraft. The Russian senator stressed that Iran, Turkey and Central Asian states may assist Russia with regard to its humanitarian mission in Syria.