SEOUL�South Korea�s president heads to Iran on Sunday targeting billions of dollars of economic and energy deals in a landmark visit. Also expected on the agenda: Squeezing North Korea�s ties to a traditional ally.

President Park Geun-hye will help establish a �foundation of cooperation� with Iran by becoming the first South Korean president to visit Tehran since the nations established diplomatic ties in 1962, a presidential spokesman said ahead of the visit.

She will meet Iranian President Hassan Rouhani on Monday and possibly hold talks with Supreme Leader Ayatollah Ali Khamenei. If the meeting with Mr. Khamenei takes place there would likely be �exchanges of opinion about the North Korean nuclear issue,� the spokesman said.

As part of a tougher policy to try to bring North Korea to talks, Seoulis prioritizing putting pressure on Pyongyang, including by targeting its links with long-standing trade and military partners.

�She has tried to pull away Pyongyang�s allies and Iran would be a big win if she can succeed in reducing cooperation,� said Robert Kelly, a professor of international relations at Pusan National University in South Korea.

South Korean officials also say Seoul sees Tehran�s decision last year to roll back its nuclear program in exchange for the lifting of international sanctions as a possible model for North Korea. Pyongyang rejects the comparison and says it won�t give up its nuclear weapons while it is threatened by the U.S. with nuclear attack.

Iran and North Korea have had ties in missile development and supply dating back to the Iran-Iraq war in the 1980s, when Pyongyang supplied Scud missiles to Tehran.

Earlier this year, the U.S. Treasury sanctioned an official in an Iranian organization that it alleged has sent missile technicians to North Korea in recent years to work on a rocket booster being developed by Pyongyang.

U.S. officials have also expressed concerns about possible cooperation in nuclear technology between North Korea and Iran, such as sharing of technology or test data. In January, North Korea detonated a nuclear device at a test site, which it called its first test of a powerful hydrogen bomb.

Ms. Park said on Thursday that Pyongyang appeared to be ready to hold another nuclear test �anytime it decides to do so.�

In response to a question from The Wall Street Journal, Iran�s ambassador to South Korea said last year that there was no cooperation by Tehran with Pyongyang over missile and nuclear technology.

Iran and North Korea also have diplomatic and trade links, and Tehran has supported Pyongyang in international institutions, including by voting against United Nations� motions condemning North Korea�s human rights record.

In 2012, North Korea�s titular head of state visited Tehran and signed an agreement for the expansion of mutual cooperation in scientific, academic and technological know-how between the two countries, according to Iranian media.

Daniel Pinkston, an expert in the two Koreas based at Troy University in Seoul, said it was highly likely that Ms. Park and her delegation would privately raise U.N. sanctions banning North Korea�s trade in missiles and other weaponry during the visit.

�I can�t imagine her not having national security issues on her agenda,� he said.

Officials in Seoul say the primary purpose of the visit is economic as Korean companies eye deals in areas such as construction, autos and electronics. Ms. Park will be accompanied by Seoul�s biggest-ever traveling business delegation of over 230 executives during the three-day visit.

East Asian nations are scrambling to boost economic links with Tehran after it won relief from international sanctions last year by agreeing to restrictions on its nuclear program. Chinese President Xi Jinping visited Iran in January and Japan signed an investment treaty with Iran a month later.

South Korea is also eager to boost its oil supply from Iran which used to account for 10% of its oil imports before sanctions were imposed.

The economic benefits that Iran�s nuclear deal bring to Tehran could be helpful in trying to persuade North Korea to rethink its own nuclear commitment, some analysts say.

�She is sending a message that if North Korea wants to show a positive gesture on denuclearization then South Korea is ready to talk,� said Go Myung-hyun, a North Korea expert at the Asan Institute for Policy Studies, a Seoul-based think tank.

This article was written By�Alastair Gale for The Wall Street Journal on April 28,2016.