U.S. President Donald Trump touched down in Saudi Arabia aboard Air Force One on Tuesday on the first stop of four day visit to the region, the first major overseas trip of his second term, with a focus on securing investment in the U.S. economy worth as much as $1 trillion. Trump was greeted by the kingdom's de facto ruler Crown Prince Mohammed bin Salman and went straight into an arrival ceremony in the airport terminal in Riyadh, joined by Secretary of State...