The White House has threatened to impose sanctions on countries that maintain ties with Iran.
Turkey's president has argued against severing economic ties with Iran as the United States readies for sanctions.
Speaking in Ankara, President Recep Tayyip Erdogan said it goes against the independence of states to cut ties with its "neighbor and strategic partner" because the U.S. demands it.
President Donald Trump announced in May that he would pull out of an international nuclear agreement reached in 2015, meant to curb Iran's controversial nuclear aspirations, and plans to reimpose sanctions. His administration threatened countries with sanctions if they do not cut off Iranian oil imports by early November.
Turkey imported 3 million tons of crude oil from Iran in the first four months of 2018, amounting to 55% of crude supplies and 27% of its total energy imports.
Erdogan asked Wednesday: "Who will heat my country throughout the winter?"
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