Russian use of Iranian bases unfortunate, but not surprising

WASHINGTON - Russia's use of an Iranian air base to carry out military strikes in Syria is "unfortunate but not surprising," a US State Department official said on Tuesday, adding Washington is still assessing the extent of Russian-Iranian cooperation.
State Department spokesman Mark Toner said Russia's use of the Iranian bases would not necessarily prevent the United States from reaching a deal with Moscow to cooperate in the fight against Islamic State in Syria.
But he added that "we're not there yet" on a cooperation agreement, noting that Moscow has continued to strike moderate Syrian forces supported by the United States.