Russia’s foreign ministry pushed back Monday at the U.S. warning that the Kremlin was escalating the conflict in Syria, arguing that its policy to support President Bashar al-Assad’s government in the fight against extremists has been longstanding. “We have always supplied equipment to them for their struggle against terrorists,” said Foreign Ministry spokeswoman Maria V. Zakharova. “We are supporting them, we were supporting them, and we will be supporting them” in that battle. Secretary of State John Kerry called his Russian counterpart, Sergey Lavrov, on Saturday to warn against sending military aid to Syria. Zakharova added that expanding military aid was part of President Vladimir Putin’s policy to combine efforts in the fight against ISIS. Also Monday, Greece’s foreign ministry said it was examining a U.S. request to prohibit Russia from using Greek air space for aid flights to Syria, Reuters reports.