Riyadh | Crown Prince Mohammed bin Salman welcomed President Donald Trump to Saudi Arabia on Tuesday as the US leader began a four-day Middle East tour.

Trump, as he did in his first term, is paying an early visit to the kingdom after the crown prince promised to pump hundreds of billions of dollars in new investments in the United States.

The US administration said it intended to use the trip to launch economic agreements with the Saudis as well as the governments of Qatar and United Arab Emirates later this week.

But behind closed doors, the leaders of all three countries are aiming to get a bead on US efforts to dismantle Iran's nuclear programme, end the war in Gaza, hold down oil prices and more.