RIYADH, Saudi Arabia (Diya TV) — Saudi Arabia’s Crown Prince Mohammed bin Salman said on Thursday that the kingdom will invest $600 billion in the United States over the next four years. The announcement was made after the crown prince made a phone call to President Trump to discuss bilateral trade and cooperation.

The Saudi Press Agency reported that the crown prince expressed the kingdom’s commitment to expand investments and trade with the U.S., potentially surpassing the initial $600 billion target. However, details on the specific sectors for these investments were not disclosed.

The two leaders touched on fostering peace and stability in the Middle East. Although relations between the nations have remained volatile, Saudi Arabia has been focused on diversifying its economy to be less reliant on oil and to ensure greater diversification into the global supply chain. More recently, sovereign wealth funds based in Saudi have acquired major holdings in U.S. businesses; and the kingdom has also refocused its investment and efforts in sports as well as infrastructural development.

The White House hasn’t commented on the conversation, and it’s still unknown whether this was Trump’s first call with a foreign leader since returning to office.

Trump, who kept a tight relationship with Saudi Arabia throughout his presidency, already indicated he would go to the kingdom again on his first trip abroad as the president did in 2017 when Saudi Arabia committed to the purchase of U.S. goods worth $450 billion.