"The chance of something going wrong - you insult the hosts, you get sick, your boss gets sick, you miscommunicate with your hosts, you make a scheduling error, you need to change the schedule just hours before a meeting, the motorcade get stuck in traffic, or the plane is stranded due to bad weather - is extremely high", said Julianne Smith, who served as a foreign policy adviser to Vice President Joe Biden and is now a senior fellow at the Center for New American Security.
The Washington Post, citing sources familiar with the matter, did not identify the senior Trump adviser except to say that the person of interest was close to Trump, a Republican who entered the White House four months ago.
Netanyahu's February visit to the White House included a press conference at which both he and Trump demonstrated a strong personal bond and lavished praise on each other.
It is the first time a United States president has chosen Saudi Arabia as the first stop on a maiden trip.
Be Civil - It's OK to have a difference in opinion but there's no need to be a jerk.
Trump remains popular in the Gulf, where leaders hope he'll take a harder line on Iran than his predecessor Barack Obama.
This isn't to say that major United States media shouldn't note when U.S. leaders glad-hand despotic governments-they certainly should. Billboards featuring images of Trump and the king dotted the highways of Riyadh, emblazoned with the motto "Together we prevail".
"We would like to have one single message, that we are all united against extremism and terrorism", says Awwad Al Awwad, Saudi Minister of Cultuer and Information.
But the Israeli leg of his trip is already awash in controversy - from a row over his visit to Jerusalem's Western Wall, the holiest prayer site for Jews, to Trump's alleged disclosure of Israeli intelligence to Russian officials.
He added that the kingdom would like to see more "decisive statements, actions and sanctions on the Iranian regime".More news: WannaCry is your fault - Microsoft to NSA
Top regional ally Saudi Arabia has said the trip will conclude political and commercial agreements and will help bolster the joint fight against Islamist militants. "Great to be in Riyadh, Saudi Arabia". A measure he has issued since taking office to impose a temporary travel ban on people from six Muslim-majority countries has been blocked by courts.
Actually, no. Thus far, the LA Times, CNN, NBC, MSNBC, CNN, ABC and CBS haven't reported on Trump's massive arms deal with Saudi Arabia, much less had a pundit or editorial board condemn it.
On Saturday, Trump is expected to announce an arms deal with Saudi Arabia worth more than $100bn, in what could be the biggest such agreement in history. The package includes tanks, combat ships, missile defense systems, radar and communications and cybersecurity technology.
Breaking with the precedent of an American president making his first foreign visit to Canada - though George W. Bush opted to go to Mexico first - Trump departs Washington on Friday to visit Mecca, Jerusalem and Rome, before squeezing in a few days of sybaritic summitry typical of North Atlantic Treaty Organisation and the G7.
The Trump administration separately informed Congress on Friday that it will sell some $500m in precision-guided munitions to Saudi Arabia.
WE are waiting for the grand summit between the west led by Donald Trump and the Arab and Muslim world in Riyadh the capital of Saudi Arabia, led by the Custodian of the Two Holy Mosques King Salman. On Tuesday, Trump is expected to meet with Abbas in Bethlehem.
National security adviser H.R. McMaster told reporters on Thursday that Trump would deliver a speech in Saudi Arabia expressing hope that a peaceful vision of Islam would resonate worldwide.
In another development, the Washington Post said a current White House official close toTrump was a significant "person of interest" in the investigation into possible ties with Russian Federation.
After two days of meetings in Riyadh, Trump will travel to Israel, have an audience with Pope Francis at the Vatican, and meet with allies at a North Atlantic Treaty Organisation summit in Brussels and the Group of 7 wealthy nations in Sicily.