Saudi Arabia signed billions of dollars of deals with USA arms manufacturers and energy companies, including Lockheed Martin, Boeing, Raytheon, General Dynamics, Northrop Grumman, General Electric, Exxon Mobil, Halliburton, Honeywell, McDermott International, Jacobs Engineering Group, Rowan Companies, National Oilwell Varco, Nabors Industries, Weatherford International, Schlumberger, and Dow Chemical. Earlier this week the Senate debated and then shelved a resolution calling for an end to US support for the Saudi-led coalition in Yemen.
Created at the end of the Second World War by Franklin D. Roosevelt and Saudi Arabia's founder, King Abdulaziz, the relationship has long guaranteed the U.S. oil security in return for its protection and continued support of the Saudi regime.
The visit certainly got off to a good start, with Mr Trump remarking on the current state of US-Saudi ties, "The relationship is probably the strongest it's ever been".
The history that passed between the two pictures, that of the Crown Prince during his visit to the United States and the one featured behind him, reflect the depth of relations between the two nations.
"We'll see what happens", Trump said.
U.S. President Donald Trump gave a warm welcome to Saudi Arabia's Crown Prince Mohammed bin Salman on Tuesday and credited U.S. defense sales to the Saudis.
Saudi Crown Prince personally manages the economic portfolio as president of the Supreme Economic Council, making many of his previous tasks have been characterized as economic in addition to being political.
The crown prince oversaw the invasion of Yemen as defense minister in 2015.
The Obama administration also halted some USA arms sales to Saudi Arabia over concerns about civilian deaths in neighboring Yemen, where Saudi Arabia is waging war against Iranian-backed rebels.
Trump said that the Saudis were "also footing a big part of the bill for defense" in "the whole Middle East" but made clear that he expects Riyadh to do more.Referring to the almost completed battlefield defeat of the Islamic State in Iraq and Syria, Trump said that USA involvement was "coming to an end in that part of the world".
Donald Trump chose Saudi Arabia as the location for his first official overseas visits, a symbolic decision that reasserted the country's position as America's pre-eminent ally in the Middle East.
Prince Mohammed later met with Republican Senators Dan Sullivan, Tom Cotton, and Lindsey Graham, along with Democratic Senator Joe Manchin, in talks which the Saudi embassy said showed the "multidimensional" nature of the kingdom's relations with the US.
It's not the only regional mess the Saudis are in.
As the 32-year-old heir to the Saudi throne began his PR offensive, however, Congress was debating reducing military aid to Saudi Arabia because of alleged atrocities in the war in Yemen.
In November, US officials voiced unease when Lebanon's prime minister unexpectedly resigned while in Riyadh.
The rift between Iran and Saudi Arabia is another reason why Bin Salman is hell bent to buy multibillion-dollar arms. There is now a growing expectation in Washington that the Trump administration will walk away from the nuclear deal later this year, using Iran's continued development of its ballistic missile programme and its unwanted meddling in the affairs of Arabs states as an excuse. Stock exchanges in NY and elsewhere are vying for the worldwide listing of Aramco, the Saudi oil behemoth expected to go public soon.