South Korea and Saudi Arabia signed a memorandum on nuclear cooperation during a visit by President Park Geun-Hye that began Tuesday, official media said.
The two sides reached a "memorandum of understanding in the field of nuclear cooperation programmes", a partnership in research and skills development, the state Saudi Press Agency said.
South Korea's Minister of Science, ICT and Future Planning, Choi Yang-hee, signed the memorandum with Saudi official Hisham bin Abdullah Yamani, SPA said.
Earlier, Jungho Lee, head of the political section at Seoul's embassy, told AFP there would be a "framework agreement" on technical cooperation, research and development and the exchange of personnel in the nuclear field.
He said the agreement is between King Abdullah City for Atomic and Renewable Energy (K.A.CARE) and Choi's ministry.
Saudi Arabia is the world's biggest petroleum exporter and entirely dependent on oil and gas for its electricity production.
The late King Abdullah established K.A.CARE in 2010 to develop alternate energy, including atomic power.
SPA said the signing took place after Park and King Salman held talks on "aspects of cooperation".
Ministers also signed two other economic pacts, including one on sea transport, SPA said.
South Korea is Asia's fourth-largest economy and imports nearly all of its energy supplies.
Park's visit is the first by a South Korean president since 2012.
The two nations enjoy "traditional friendly relations" but this is a chance to strengthen ties and discuss "topics of common interest" after Salman acceded to the throne in January following Abdullah's death, Lee said.