President Trump arrived on Tuesday morning in Saudi Arabia, his first stop on a four-day tour through the Gulf, the first major overseas trip of his second term. He stepped off Air Force One at the Royal Terminal, a special section for V.I.P.s at King Khalid International Airport in Riyadh, the Saudi capital. Mr. Trump was greeted by Crown Prince Mohammed bin Salman, the kingdom’s de facto ruler, on a lavender-colored carpet unfurled across the tarmac. An honor guard was in place. Mr. Trump and Prince Mohammed then sat down in navy-and-gold armchairs in an opulent, sunlit building with marble columns. Mr. Trump was accompanied by Secretary of State Marco Rubio and Defense Secretary Pete Hegseth, among others. Prince Mohammed’s presence signified the special status that Mr. Trump enjoys with Saudi Arabia. When President Biden visited in 2022 — after saying he would make the kingdom a “pariah,” before realizing he needed its help to lower oil prices — the crown prince snubbed him, sending a relatively low-ranked delegation to greet him at the airport.