WASHINGTON -- The United States' position on Iran sanctions remains unchanged, a State Department spokesperson said Monday, amid Iran's continued demand for the release of its money blocked in South Korean banks.

"The United States' position on Iran sanctions has not changed," the department spokesperson told Yonhap News Agency in an email, asking not to be identified.

The remarks come after South Korean Prime Minister Chung Sye-kyun noted the money belongs to Iran.

"I have said before that this money is Iran's money and should be returned to its owner," Chung told reporters while on a visit to Tehran.

Chung, however, noted they must first find a way to return the money to Iran.

Iran currently has about $7 billion frozen in South Korean banks due to US sanctions.

Washington earlier said the money will not be released until Iran returns to compliance with its multilateral nuclear deal, known as the Joint Comprehensive Plan of Action.

"As we've said, if Iran comes back into compliance, with its obligations under the nuclear agreement, we would do the same thing that would involve, if it came to that, if Iran made good on its obligations, sanctions relief pursuant to the agreement," US Secretary of State Antony Blinken has said.

Seoul-Teheran negotiations over the frozen Iranian funds surfaced after Iran seized a South Korean tanker in January, though it claimed the seizure had nothing to do with its money locked in South Korea.

Iran released the tanker and its captain last week.

Chung's visit to Iran marked the first of its kind by a South Korean prime minister in 44 years. (Yonhap)