US officials 'alarmed' over Mohammad bin Salman's 'reckless behaviour'

US officials have expresed concern over Crown Prince Mohammad bin Salman's "reckless" actions in recent weeks to consolidate power in Saudi Arabia.

Speaking to the New York Times, an unnamed State Department official also said the 32-year-old prince's behaviour "has the potential to damage US interests".

With little experience in government, bin Salman, known as MbS, has risen to power in just three years to oversee all major aspects of politics, security and the economy in Saudi Arabia. As defence minister, he is in charge of the Saudi-led war in Yemen against Houthi rebels.

On November 4, he ordered the arrest of princes, ministers and high-profile businessmen allegedly in a corruption crackdown.

On the same day, Lebanese prime minister Saad Hariri announced his shock resignation from Riyadh.

"He's decided he doesn't do anything cautiously," said Philip Gordon, who was White House Middle East coordinator under President Barack Obama.

But, Gordon said: "If the crown prince alienates too many other princes and other pillars of the regime, pursues costly regional conflicts and scares off foreign investors, he could undermine the prospects for the very reforms he is trying to implement."

Bin Salman, however, appears to have the support of US President Donald Trump and his son-in-law, senior adviser Jared Kushner, who visited the Saudi capital earlier this month.

Kushner has made three visits to Saudi Arabia in the past year. He had not declared his last visit until he returned to Washington. It was said that Kushner and bin Salman stayed up talking through the night, but the content of the meetings were undisclosed days before the Saudi purge began.

American officials were said to have been apprehensive about the relationship between Kushner and bin Salman.

"Jared is a bit of a black hole," the State Department official told the Times under anonymity. "There is no sense of the positions he has advocated. We can only guess, based on what he has done and where he has been."

"The Emiratis and the Saudis have been very careful to cultivate him and bring him along" toward their "confrontational posture in the region", the official added.

"I have great confidence in King Salman and the Crown Prince of Saudi Arabia, they know exactly what they are doing," President Trump said on Twitter after the mass arrests. 

The State Department official, though, said that its diplomats, the Pentagon and the Central Intelligence Agency all felt "growing alarm" that bin Salman "is behaving recklessly without sufficient consideration to the likely consequences of his behaviour, and that has the potential to damage US interests."