During a phone call, Saudi Crown Prince Mohammed bin Salman pledged to invest $600 billion in the United States over the next four years.
He expressed confidence that the Trump administration's policies would foster significant economic growth.
The report said Saudi Arabia wants its investments to capitalize on these conditions.
It did not detail the source of the $600 billion, whether it would be public or private spending nor how the money would be deployed.
Trump fostered close ties with Gulf states including Saudi Arabia during his first term. The country invested $2 billion in a firm formed by Jared Kushner, Trump's son-in-law and former aide, after Trump left office.
Trump said following his inauguration on Monday that he would reflect making Saudi Arabia his first destination for a foreign visit if Riyadh agreed to buy $500 billion worth of American produces, similar to what he did in his first term.
"I did it with Saudi Arabia last time because they agreed to buy $450 billion worth of our product. I said I'll do it but you have to buy American product, and they agreed to do that," Trump said.
During his first administration, Trump actively seen Saudi Arabia, long an important energy and security partner for Washington.
