South Korea has called on North Korea to repay millions of dollars in loans provided years ago, an official said Friday, amid no signs of progress in resolving the issue. North Korea is required to pay back US$8.6 million to South Korea on Monday as the first repayment of principal and interest of assistance worth $80 million extended to the North in 2007, according to the official of the unification ministry. The North is obligated to repay a total of $86.03 million, including interest, to South Korea over the next 10 years, the official said. South Korea's state-run Export-Import Bank sent a message to its North Korean counterpart last month to inform the North of its obligation, the official said. Still, the North has yet to reply to South Korea's message. In 2007, South Korea provided the North with US$80 million worth of raw materials to help it produce clothing, footwear and soap in return for North Korea's minerals, such as zinc. Separately, South Korea provided rice and corn in loans worth $724 million to North Korea between 2000 and 2007, during which two liberal South Korean presidents sought reconciliation with North Korea. Still, North Korea has since missed the deadline twice to repay South Korea $11.61 million in principal and interest of the $724 million food loans. South Korea has sent messages to North Korea on eight separate occasions to repay its debt, but the North has kept silent on Seoul's repeated demands. South Korea says the North is required to pay back a total of $961.53 million by 2037, including principal and interest of food loans and assistance of raw materials.