South Korea's vice foreign minister is meeting this week with the top negotiators of the countries involved in reviving the 2015 Iran nuclear deal.
Seoul's foreign ministry said Thursday that Vice Minister Choi Jong-kun has already met with five of them separately in Vienna, where the negotiations are taking place.
These meetings were with representatives of the U.S., the EU as well as France, Germany, and the U.K.
Choi said the current round of negotiations has reached "a critical juncture" and called for efforts to achieve "positive progress."
Seoul is not one of the negotiating parties, but it has some unresolved issues related to Iranian funds.
Under the U.S. sanctions, Some 7-billion dollars' worth of Iranian oil money is frozen in two South Korean banks.