Saudi Arabia has relieved Muhammad bin Nayef from his role as crown prince, replacing him with Mohammad bin Salman, according to a royal decree published by state news agency SPA.

Bin Salman, 31, has been his country’s defense minister and deputy crown prince, and was recently credited with a “huge success” for President Donald Trump’s recent decision to stop in Saudi Arabia.

Saudi Arabia’s King Salman called for a public pledging of allegiance in Mecca on Wednesday to the new crown prince, Saudi-owned channel al-Arabiya said on Wednesday.

The young prince has taken a central role in Saudi Arabia’s efforts to build its economy beyond the oil industry. He holds primary responsibility for the kingdom’s military and energy sector.

In March, Bin Salman met Trump in the White House, and agreed that Iran represents a regional security threat.

Here’s CNBC’s look at Bin Salman’s economic vision for his country.

In May, the then-deputy crown prince said his radical economic reforms were succeeding in protecting the kingdom against low oil prices, and he promised massive investments in coming years to help diversify the economy beyond oil.

Experts have said that Bin Salman is different than other Saudi leaders in that he had been educated in the kingdom — he wears traditional dress and is popular with young Saudis.

“They see in Mohammad bin Salman someone of their own generation moving up the ladder very quickly. He has a certain degree of popularity. He’s also grated a lot of people in the family who see him as abrasive, inexperienced, undisciplined, impulsive,” Bruce Riedel, director of the intelligence project at Brookings and former CIA national intelligence officer for the Middle East, told CNBC in 2016.

This is breaking news. Please check back for update.

—Reuters and CNBC’s Patti Domm and Berkeley Lovelace Jr. contributed to this report.