Seoul, South Korea: The leaders of South Korea and Saudi Arabia agreed Thursday to boost ties in key sectors such as energy and defence, with the oil-rich kingdom signing a slew of deals including a $6.7 billion petrochemical agreement.

President Yoon Suk-yeol met with Saudi Arabia's Crown Prince Mohammed bin Salman in the South Korean capital Thursday, announcing a plan to transform bilateral ties into a "strategic partnership".

Bin Salman, the kingdom's 37-year-old de facto ruler, often referred to as MBS, arrived in Seoul late Wednesday after attending the Group of 20 summit in Bali, Indonesia.

Yoon and bin Salman agreed to elevate ties into a "future oriented strategic partnership," Yoon's office said in a statement.

The South Korean president wants to see local companies join key Saudi projects such as the futuristic mega-city known as NEOM, and boost cooperation in the defence and energy sectors.

Bin Salman "especially expressed his wish for a significant increase in cooperation in energy, defence and construction industries," Yoon's office said.

During the visit, the two governments and companies from both countries -- including some of Seoul's top conglomerates -- signed about 20 deals in areas from agriculture to railways.

The Saudi investment ministry said the agreements were worth roughly $30 billion and covered sectors including energy, manufacturing, financial services and pharmaceuticals.

Among the agreements was Saudi investment for South Korean refiner S-OIL's Shaheen project, which would build petrochemical production facilities in South Korea worth $6.7 billion, Yoon's office said.

Bin Salman has tried to jumpstart efforts to diversify the economy of Saudi Arabia, the world's biggest crude exporter, away from oil and to grow the private sector, and Saudi officials look to South Korea as a possible model.

"Driven by the private sector, Korea's successful economy and the global positioning of so many Korean companies, which are household names, are testament to Korea's strategy's success," Saudi investment minister Khalid al-Falih said.

"The Korean model has been a benchmark for Saudi Arabia's Vision 2030 and National Investment Strategy, which aim to increase the private sector's contribution to the economy to 65 percent of GDP by the end of this decade."

- Asia tour -

Bin Salman is on a multi-stop Asian tour in a bid to shore up the Gulf nation's ties with its biggest energy market.

He left South Korea on Thursday for Bangkok, where he is scheduled to attend the Asia-Pacific Economic Cooperation (APEC) forum.

The trip comes as Riyadh feuds with Washington over the OPEC+ oil cartel's October decision to cut production by two million barrels per day.

Bin Salman, who was officially made prime minister in September, has shaken up the ultraconservative oil titan with economic, social and religious reforms since his meteoric rise to power.

He gained global notoriety in connection with the 2018 killing of dissident Saudi journalist Jamal Khashoggi in the kingdom's Istanbul consulate.

Last year, US President Joe Biden declassified an intelligence report that found bin Salman had approved the operation against Khashoggi, an assertion Saudi authorities deny.

© Agence France-Presse