Saudi Arabia’s King Salman promoted his son Mohammed bin Salman to crown prince on Wednesday, a surprise announcement that means the 31-year-old becomes the kingdom’s next in line to the throne.

The decision upends the royal line of succession in a key ally of the United States in the Middle East that President Trump visited in his first overseas trip as president.

As part of the move, King Salman stripped Prince Mohammed bin Nayef from his title as crown prince and from his powerful position as the country’s interior minister overseeing security.

The overhaul was made by royal decree carried on the state-run Saudi Press Agency.

Mohammed bin Nayef, 57, was a figure well-known to Washington and the newly announced Crown Prince Mohammed bin Salman’s cousin, who had previously been second in line to inherit the throne of the Arab world’s largest economy.   

Mohammed bin Nayef was known for cracking down on al-Qaeda bombing campaigns in the country.

Crown Prince Mohammed bin Salman already oversees a vast portfolio as defense minister and heads an economic council tasked with overhauling the nation’s economy.

His elevation comes as Saudi Arabia faces escalating tensions tensions with neighbors Qatar and Iran over their support for Islamist groups and as it is involved in a devastating air war in Yemen that has killed thousands of civilians.

He visited Washington in March and had lunch at the White House with Trump. In an interview with the Washington Post, he praised U.S. leadership and said that without its influence abroad Saudi Arabia “would have ended up like North Korea.”

The new crown prince has also expressed support for improving human rights and freedom of expression in a country that is widely criticized for its oppressive laws.

Human Rights Watch says that Saudi authorities continue to make arbitrary…