TEHRAN -- South Korea's prime minister said Monday his country is willing to provide "sideline" support for Iran to advance "productive" dialogue with partners in restoring the 2015 Iran nuclear deal.

Chung Sye-kyun made the remarks during a joint press conference Sunday (local time) with Iran's First Vice President Eshaq Jahangiri in Tehran following their 90-minute talks.

Chung was visiting Iran for a three-day itinerary till Tuesday to discuss bilateral ties amid lingering tension over Tehran's call to unlock its funds of $7 billion frozen in South Korea under US sanctions. It marks the first such trip to the Middle Eastern country by a South Korean premier in 44 years.

With regard to the frozen fund, the prime minister said South Korea "needs to step up cooperation with related nations including Iran" to settle the issue.

His remarks mirror the South Korean government's commitment to settling the issue by lending support to Iran in its process to restore the nuclear deal with the United States, Britain, France and Germany.

The fund issue has been a major diplomatic thorn between Seoul and Tehran, and has been widely attributed as the reason behind Iran's seizure of a South Korean oil tanker and its crew members in early January. Tehran liberated the ship and its captain last week.

During their meeting Sunday, the Iranian vice president once again prodded Chung to unlock its frozen funds as soon as possible.

The two sides also agreed to expand humanitarian cooperation, possibly including medical exchanges, and to install a special consultative body that will be in charge of preparing for economic cooperation projects to be pursued after the potential restoration of the Iranian nuclear deal.

Chung also called for the prevention of Iran's detention of foreign ships in the future, saying, "The freedom of navigation should be guaranteed."

"This latest visit to Tehran is the expression of South Korea's commitment to building a forward-looking relationship between the countries," the prime minister also noted.

On Monday, Chung was to meet with top Iranian officials, including Mohammad Bagher Ghalibaf, the Iranian parliamentary speaker.

The prime minister was also seeking to hold a meeting with Iranian President Hassan Rouhani before his return to Seoul on Tuesday. (Yonhap)