Donald Trump hailed a "tremendous day" on Saturday after signing deals worth hundreds of billions of dollars during a visit to Saudi Arabia in which he received a lavish welcome.

Mr Trump arrived with his wife Melania in Riyadh on Saturday morning for a state visit to the Gulf kingdom on the first leg of his debut foreign tour as his administration remained locked in turmoil back home.

"That was a tremendous day. Tremendous investments in the United States," Mr Trump said. "Hundreds of billions of dollars of investments into the United States and jobs, jobs, jobs."

He received an elaborate welcome and was met on the tarmac by King Salman bin Abdulaziz Al-Saud, before holding talks with the monarch and crown princes.