The announcement was made by the Iraqi Ministry of Electricity on Wednesday, which said the payment process had begun on the same day.
Iraq is paying its overdue money to Iran following several high-level meetings between the two countries in the past months.
Iraqi officials have previously said that their country should pay the debt, which amounts to $1.750 billion, in order to be able to import more gas from Iran.
According to the officials, Iraq needs to import 50 million cubic meters of Iranian gas per day during this summer and up to 20 million cubic meters a day in the winter.
Iraq mostly uses the imported gas to feed its power grid and produce electricity amid high domestic demand.
The demand increases in the summer due to scorching weather conditions in the Arab country.
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