WASHINGTON - Most US presidents make their first foreign trip an easy-peasy one-day hop to visit friendly neighbors in Canada or Mexico, but not Donald Trump.

On Friday the 70-year-old president will go "yuge" -- embarking on an eight-day six-stop behemoth trip that would test an experienced administration and may push his already weary staff to breaking point.

For bystanders snapping pictures of the motorcade as it whizzes though the emptied streets of a foreign capital, presidential travel looks graceful, maybe even enjoyable.

But behind the scenes is a steeplechase of tension, tears, jetlag and sleep deprivation.

If Trump is looking for a break from the rolling scandals plaguing his White House, foreign travel will offer a change of scenery, but little respite.

The tempo is relentless, and the political stakes could not be higher.

"What makes it especially difficult is the fact that virtually every second of the president's time, every step he takes is carefully plotted," said Ned Price, a former spokesman for Barack Obama's National Security Council.

        - Hard landing -

Even before Trump's feet hit the hot desert tarmac in Saudi Arabia -- after a long overnight flight on Air Force One -- the show is underway.

As Obama found out the hard way, everything -- down to the choice of aircraft steps -- can become a presidential-scale problem.

Last September, when Secret Service agents in Hangzhou could not find a red-carpet step operator who spoke English, the call was made for Obama to exit from steps that fold out from the belly of the plane.

The outcry was swift. "They won't even give him stairs, proper stairs to get out of the airplane. You see that?" then candidate Trump chimed in, seeing evidence of a snub.

"I've got to tell you, if that were me, I would say, 'You know what, folks, I respect you a lot but close the doors, let's get out of here.'"

By the end of his visit to Saudi Arabia, Israel, the Palestinian territories, the Vatican, Brussels and Sicily, Trump may be a little more understanding.

In some ways, Trump's visit has already begun. Around a month beforehand, a platoon of officials from the White House, Secret Service, military and National Security Council walk through each and every step.

Protocol officers discuss what flag goes where, and the president's doctors scout hospitals for requisite facilities in case of the unspeakable.

The aim is to make sure any logistical problems are solved before Air Force One -- filled with aides, Secret Service, the traveling press and of course the president -- lands, along with a chase plane full of staff and military transport aircraft carrying everything from podiums to "the Beast" -- the president's hardened limousine.

For staff and other travelers, days normally begin before dawn and after perpetual movement end long after dusk -- if they end at all. Food comes in boxes, if at all.

- Away from staff -

A typical day could involve a bilateral meeting, a welcome ceremony, several summit sessions on everything from trade to security, a family photo, a concert and a working dinner.

At each step the president will have to hit his mark, sounding the right message, making "asks" and ensuring "deliverables" -- or concrete deals -- come through.

Not even the act of moving a president from point A to point B -- be it just down the hall, is straightforward.

Rooms have to be swept by Secret Service, areas secured and unwelcome political figures kept at arm's length.

Staff will have to "work through POTUS time and DC time," facing crises with difficult communications across time zones, said Loren DeJonge Schulman, another Obama National Security Council.

Trump himself will face the challenge of being far from his staff and usual sources of information.

"For a man accustomed to watching cable news all day, foreign POTUS travel will be like sensory deprivation," Schulman tweeted recently.

  - Policy pitfalls -

Despite the best laid efforts, some things just happen.

"Anything -- from a hot mic to a protocol gaffe -- will have outsized consequences when the president is on foreign soil," said Price.

If the logistical problems were not enough, the policy pitfalls of giving a speech on Islam in Saudi Arabia, or musing about the peace process in the powder keg Middle East are obvious.

The sheer scale of the trip has left some on the president's staff with trepidations.

Many privately admit they are happy not to be involved in transplanting the malaise of the Trump White House thousands of miles east -- under even more stressful conditions.-AFP