By Kwanwoo Jun

South Korea has laid out plans for nearly $2 trillion of investment in semiconductor industries and artificial-intelligence infrastructure, with memory-chip leaders Samsung Electronics and SK Hynix committing to substantial new investments.

More than 3 quadrillion won will be spent in the coming years to create fresh chip and AI industry hubs in South Korea.

The expansion aims to deepen South Korea's role in the AI supply chain at a time when semiconductor chips are experiencing a boom in demand due partly to the global rollout of data centers. It also aims to fend off competition in production of advanced chips, including from the U.S. and China.

SK Hynix and Samsung--alongside Micron Technology of the U.S.--are the world's leading suppliers of high bandwidth memory chips, which are crucial parts of Nvidia's AI accelerators and other advanced memory products for AI applications.

The two Korean chip makers have become trillion-dollar companies as institutional and mom-and-pop investors have piled into their stock, with the latter group often relying on debt to fund purchases. South Korea is the best-performing share market in the world this year, but the dominance of the two companies has fueled wild swings in local equities that have unsettled regulators and led to occasional trading halts to steady nerves.

South Korea's industry minister said at a televised government briefing on Monday that he expects the government and companies to invest around 800 trillion won to build new chip-making hubs in southwest Korea, 81 trillion won to build chip-packaging facilities in central Korea and 30 trillion won to secure an early foothold in emerging chip markets over the next 15 years.

Meanwhile, the nation's science minister said he expects more than 1 quadrillion won to be invested by both the government and companies in building AI data centers by 2035.

The briefing was chaired by President Lee Jae Myung, who has called for large-scale investment in South Korea's semiconductor and AI industries, including robotics and AI data centers, while pledging strong government support for relevant businesses.

SK Group Chairman Chey Tae-won said mobile carrier SK Telecom plans to build 15 gigawatts of AI data center capacity in Korea.

Chey also said Nvidia supplier SK Hynix plans to invest 1.100 quadrillion won to expand its chip production in Korea in the future, and of the total, 400 trillion won has been earmarked for investment in a new facility in southwest Korea.

Samsung Chairman Lee Jae-yong said that he has picked Gwangju in southwest Korea as a strong candidate to host a new Samsung chip production hub. Samsung Electronics said in a separate statement that it and other AI-related Samsung affiliates are also expanding their investments across the country, worth 2.655 quadrillion won in total.

Write to Kwanwoo Jun at kwanwoo.jun@wsj.com