Iran has increased oil exports to South Korea fourfold since January and now hopes to triple its yearly trade with Seoul, Iranian leaders have said.
Iranian Oil Minister Bijan Zanganeh said Tehran had quadrupled its oil exports to the world's fifth-largest importer of crude, sending Seoul 400,000 barrels a day in April, up from 100,000 barrels before economic sanctions were lifted in January under a nuclear deal with world powers.
His announcement came on a day when the OPEC oil cartel rocked global markets with estimates showing that Iran increased its daily oil production to 3.5 million barrels a day last month, the most since December 2011.
That is not far from Iran's goal of reaching its 4 million-barrel output peak before sanctions were imposed.
Iran announced its ambitious new trade goals and achievements during South Korean President Park Geun-Hye's visit to Tehran, which was the first for any South Korean president since the two countries established diplomatic relations in 1962.
Park met with Iranian President Hassan Rohani and the two held a joint press conference announcing their major expansion in trade and tourism to $18 billion a year, and reestablishment of direct airline flights between Tehran and Seoul.
Park, accompanied by a delegation of more than 230 Korean business executives and aides, was also received by Iranian Supreme Leader Ayatollah Ali Khamenei.
Khamenei told Park that the United States, Korea's closest ally, should not influence Iranian-South Korean ties.
"Relations between Iran and South Korea should not be dependent on sanctions or influenced by the United States or any grudges the U.S. may hold" against Iran, Khamenei said, according to his website.
"We believe there is a possibility for more understanding, agreement and cooperation with Asian countries, including South Korea," Khamenei said.
On the first day of Park's visit on May 1, the two countries pledged to develop the energy sector.
"We will expand relations in energy projects and infrastructure...and in oil, gas, railways, and ports," Park said at the news conference with Rohani.
The two governments signed 19 cooperation agreements in the presence of the presidents, and further memorandums of understanding were due to be signed by the private sector, Rohani said.
Woori Bank opened an office in Tehran, becoming the first South Korean lender to have one, Iran's official IRNA news agency reported.
Park and Rohani also discussed the tense situation on the Korean Peninsula and fears that Pyongyang may conduct a fifth nuclear test.
Rohani urged Seoul to follow Iran's example and establish a nuclear-free zone.
"Our demand is a world free of weapons of mass destruction, especially freeing the Korean Peninsula and the Middle East from destructive weapons," he said.
With reporting by AFP and AP