WASHINGTON - US President Donald Trump on Tuesday implored Saudi Arabia’s powerful crown prince to share his nation’s wealth by continuing to purchase American-made weapons.

Trump’s focus on Saudi purchases of US military equipment came amid a bipartisan effort to limit the United States’ role in Yemen’s civil war and protests in several US cities over the Saudi-led invasion, which has contributed to a humanitarian crisis.

In opening remarks before a meeting with Crown Prince Mohammed bin Salman, Trump crowed about the sales, running through a list of $12.5 billion in approved arms purchases by Saudi Arabia and previewing billions more to come.

“Saudi Arabia is a very wealthy nation, and they’re going to give the United States some of that wealth, hopefully in the form of jobs, in the form of the purchase of the finest military equipment anywhere in the world,” Trump said.

“There’s nobody even close, as I said before, when it comes to the missiles and the planes and all of the military equipment,” Trump said. “There’s nobody that even comes close to us in terms of technology and the quality of the equipment, and Saudi Arabia appreciates that.”

Saudi crown prince received an effusive welcome at the White House from President Trump, who hailed a “great friendship” with the kingdom - but made no public mention of the sticking points in the burgeoning alliance.

In front of the cameras, it was all back-slapping, handshakes, smiles and warm words between Trump and the heir to the Saudi throne, who was seeking to burnish his leadership credentials.

“It is an honour to have the crown prince of Saudi Arabia with us,” Trump said as the pair prepared to have lunch in the Cabinet Room. “The relationship is probably the strongest it’s ever been - we understand each other.”

Prince Mohammed, who is 32 years old, was making his first visit to the White House since he cemented his role as the kingdom’s de facto political leader and embarked on economic and social reforms long sought by the west.

Trump, touching on the sensitive shaking out happening inside the kingdom, said “some tremendous things have happened since your last visit to the White House.”

“You were the crown prince, and now you are beyond the crown prince,” he said, before adding that he misses Mohammed’s father, King Salman, and hopes to see him soon.

Prince Mohammed’s reformist message and the promise of Saudi investment in the United States has endeared him to the neophyte US president - 39 years his elder - and America’s own political princeling Jared Kushner, Trump’s son-in-law.

Trump and MBS - as he is known in Washington’s corridors of power - have seen eye-to-eye on concerns about Iran’s military activism, Middle East peace, relaxing Saudi Arabia’s deeply conservative laws and over their love for big ticket mega-investments.

But an all-out PR campaign designed to burnish the crown prince’s image, and declarations that “relations have never been better,” mask several problems that could spoil the honeymoon.

As Prince Mohammed arrived in Washington, word trickled out that Saudi Aramco - the kingdom’s energy behemoth - was cooling on the idea of a stock listing in New York, something Trump has publicly lobbied for. Trump ducked a question about the issue on Tuesday.

The news was accompanied by expressions of concern about a US law that exposes Saudi Arabia to legal action over the 9/11 attacks, which Riyadh would dearly like to see removed.

“The Trump administration will not be able to offer the necessary guarantees on any changes to US law that would reassure Saudi Arabia and the IPO is simply too important to place in jeopardy,” said Ayham Kamel of the Eurasia Group, a consultancy.

Another point of friction is the war in Yemen, where Saudi Arabia leads a coalition fighting the Huthi rebels, who are allegedly backed by Iran.

That devastating two-year-old conflict was an early proving ground for the prince, then the minister of defense, but it has been beset by atrocities against civilians and strategic drift.

Just hours after the prince leaves the White House, Congress will vote on rules designed to withdraw US intelligence and reconnaissance support for the war. The measures may not pass, but are designed as a clear warning to the White House against signing a blank check.

Trump is also expected to press his guest to end a standoff with Qatar, which has wrecked Gulf Cooperation Council unity and put the US president’s plans for a US-Gulf summit at Camp David in doubt.

But the most delicate discussions could be about Saudi Arabia’s nuclear programme, which is mooted as civilian-focused but could quickly become a platform for building a weapon.