Efforts are underway to transfer Iran’s blocked monies in South Korea, according to Foreign Minister Park Jin, after Teheran’s agreement with the US to release American citizens in exchange for the release of Iranian assets.

In a phone discussion on Monday, Park told his Iranian counterpart, Hossein Amir-Abdollahian, that the nations concerned were in close touch to settle the matter, Seoul’s foreign ministry said in a statement on Tuesday.

According to the report, Park and Iran’s foreign minister agreed to boost bilateral cooperation.

The United States and Iran reached an agreement last month for the release of five U.S. citizens detained in Iran while $6 billion of Iranian assets in South Korea would be unfrozen.

The assets that had been frozen in South Korea were transferred to Switzerland’s central bank in August for exchange and transfer to Iran, South Korean media has reported.