Syrian President Bashar al-Assad (L) receives Russia's new ambassador to Syria Alexander Kinschaka (C) in Damascus, in this February 9, 2015 handout photo by Syria's national news agency SANA. REUTERS/SANA/Handout via Reuters

Russia refused to comment on the United States’ request to Greece on not allowing Russian flights to use Greek air space for traveling to Syria.

Russian president’s press secretary Dmitry Peskov said Monday that it was too early to comment on the request. "There was a corresponding statement by our Greek partners who said they were considering this request," TASS quoted the Kremlin spokesman as saying. "It is too early to speak about that until we have any reaction."

The Greek foreign ministry has confirmed that the U.S. made such a request. Reuters reported that Greece had sought to nurture closer ties with Kremlin when it was almost on the verge of an exit from the euro zone.

Russia, on the other hand, has been an ally of Syrian President Bashar al-Assad for a long time. Several Western countries including the U.S. believe that the political unrest in Syria can only be solved after Assad loses power.

While Russia claims it intends to send humanitarian aid to Syria, Washington suspects Russia is planning to help Assad with military aid. Russian news agency Pravda reported that it was an “open secret” that Russia provided military supplies to Assad.

“Russia has never made a secret of those supplies, and the Russian Foreign Ministry has made quite a number of statements about it,” it reported.

“Well, there are Russian troops in Syria, because someone has to maintain Russian military hardware and teach Syrian military men how to use and handle the equipment,” the Russian news agency added. Pravda argued deploying hardware and the presence of operating personnel for the hardware in Syria are legal and required for "international efforts to combat terrorism."