ANKARA (Reuters) - Turkey is sincere in its efforts to solve the Nagorno-Karabakh conflict and believes in Russia’s sincerity, President Tayyip Erdogan said on Wednesday, adding he had told Russia’s Vladimir Putin that they could resolve the issue together. In a speech, Erdogan said he told Putin that Armenia is using Kurdish militants in the conflict, after Putin expressed concerns in their phone call on Tuesday over increased involvement of fighters from the Middle East.