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, with the pair 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.