SoftBank Group Corp. Chief Executive Masayoshi Son on Friday said he intends to invest around five trillion won ($4.5 billion) in South Korea’s technology sector over the next decade.

A SoftBank spokesman said that during a meeting with South Korean President Park Geun-hye in Seoul, the founder of the Japanese telecommunications and internet conglomerate said he intended to invest in fields including smart robots, the “Internet of Things” and artificial intelligence, areas Mr. Son has said would be a focus for his company over the next 30 years.

It isn’t the first time Mr. Son has shown interest in the South Korean tech sector. Last year SoftBank invested $1 billion in South Korea’s largest mobile-commerce company, Coupang, which the companies said was the largest-ever internet investment in South Korea.

Friday’s meeting comes after SoftBank closed earlier this month its $32 billion deal to acquire U.K. chip maker ARM Holdings PLC in the largest acquisition of a European technology company.

Mr. Son has depicted the acquisition of ARM, which designs microprocessors that power more than 95% of the world’s smartphones, as part of a broader strategy to build artificial-intelligence functions into the kinds of devices that carry ARM-designed chips.