Turkey didn’t acquire the Russian-built S-400 air defense systems for them to collect dust and may use them, President Recep Tayyip Erdogan has said, adding the purchase was to reduce Ankara’s dependency on US arms supplies. “We will not just buy the S-400s and place them in a storehouse. We will use them if need be,” Turkish President Recep Tayyip Erdogan said on Monday, as quoted by Hurriyet daily.