SAN FRANCISCO — The Japanese business mogul Masayoshi Son pledged to President-elect Donald J. Trump nearly two weeks ago that he would invest in the United States and create about 50,000 jobs.

On Monday, Mr. Son’s conglomerate, SoftBank, took what it described as the first step in fulfilling that commitment.

By leading a $1.2 billion investment in OneWeb, which makes satellites for internet access, SoftBank said it was continuing to invest in new technology and supporting job creation in the United States. In their announcement, SoftBank and OneWeb said the investment would create nearly 3,000 jobs in the United States over four years.

“Earlier this month, I met with President-elect Trump and shared my commitment to investing and creating jobs in the U.S.,” Mr. Son said in a statement. “America has always been at the forefront of innovation and technological development, and we are thrilled to be playing a part in continuing to drive that growth as we work to create a truly globally connected ecosystem.”