TOKYO (Reuters) -SoftBank Group CEO Masayoshi Son said on Monday he has agreed with OpenAI CEO Sam Altman to set up a joint venture in Japan to offer artificial intelligence services to corporate customers.

Son is moving to deepen his exposure to OpenAI, with SoftBank looking at investing $15 billion to $25 billion in the company, Reuters reported last week.

SoftBank is also committing $15 billion to Stargate, a joint venture with OpenAI and Oracle to build AI capacity in the U.S., Reuters has reported.

The Stargate launch last month saw Son make his second appearance with Donald Trump since his election as president in November.

Japanese Prime Minister Shigeru Ishiba is yet to meet Trump in person with a meeting planned for this week.