The president’s packed schedule is filled with opportunities for Mr. Trump to slip up, publicly or privately: back-to-back discussions with the leaders of other nations, many of whom are veteran negotiators well versed in issues they care deeply about.
By contrast, it could also serve as a much-needed change of subject for a president besieged at home with an agenda frozen by scandal.
“I’ll meet scores of leaders,” Mr. Trump told Coast Guard cadets on Wednesday as he spoke at their commencement. He pledged that during his global travels he will “strengthen old friendships and will seek new partners.”
Even before heading to Connecticut for that speech, Mr. Trump was brooding in the White House over the latest broadside from the F.B.I. director he fired, James B. Comey. Planning for the foreign trip has proceeded haltingly, with Mr. Trump resisting some of the pageantry that is usually a hallmark of a president’s travels. A visit to Yad Vashem, the Holocaust memorial museum in Jerusalem, was cut short at his request.
Preparation — a standard part of the weeks before a big foreign trip — has also been hit-or-miss in recent days.
As allegations of obstruction of justice and giving secrets to Russia consumed Mr. Trump’s administration, aides sought to focus the president’s fleeting attention on the vital foreign policy issues he will confront and the nuts-and-bolts difficulty of taking the White House around the globe.
Jared Kushner, Mr. Trump’s son-in-law and senior adviser, led briefings, including one on European leaders, last week in the Oval Office. The president conferred with the defense secretary about the Middle East and discussed his Saudi Arabia meetings with his secretary of state. Among the touchy issues in Israel: whether to move the United States Embassy to Jerusalem, something the president has decided not to announce during the trip.
But even as he sat with briefing books and stacks of news clippings about global events, Mr. Trump has generally just skimmed through, according to several people familiar with his preparations. Instead, he has focused on the chaos swirling around his White House.
In an attempt to capture his interest, aides threaded Mr. Trump’s own name through the paragraphs of one of the two-page memos they wrote for him.
“You have to be prepared. These things tend to be heavily prepared on both sides so everyone knows what the expectations are,” said James B. Steinberg, a diplomat for former President Barack Obama who traveled extensively around the world. Of Mr. Trump, he said, “The fact that he doesn’t go in for the typical preparations complicates these things.”
Mr. Steinberg said Mr. Trump’s first trip should not be that difficult since he is meeting largely with allies at a time of relative peace and prosperity.
“A trip like this is an easy trip,” he said. “There’s no crisis. It’s a relationship-building trip. It’s hard for it not to be a success unless something goes wrong.”
Still, in private, Mr. Trump’s advisers acknowledge that they are concerned about his off-script eruptions, his tendency to be swayed by flattery and the possibility that foreign leaders may present him with situations he does not know how to handle. They worry he will accidentally commit the United States to something unexpected, and they have tried to caution him about various scenarios.
Mr. Trump’s last major venture overseas — a visit to one of his new golf courses in Scotland while he was campaigning for the presidency last summer — quickly went off script.
Arriving just as Britons voted to leave the European Union, Mr. Trump held a highly anticipated news conference where he bragged about predicting the outcome of the vote and waxed extensively about the beauty of his new golf course.
“This is one of the big votes in the history of Europe and Scotland and everywhere,” he said that day in June. He then spoke at length about the golf course and resort, noting a lighthouse that sits on the course.
“We’ve taken the lighthouse, which is a very, very important building in Florida — I mean, in Scotland — and we’ve taken that building and made it something really special,” he said. “It has incredible suites. Golfers will stop, and they’ll have something to eat.”
Stephen J. Hadley, who was former President George W. Bush’s national security adviser and traveled the world with him, said that White House staff members do everything they can to avoid surprises when a president is out of the country.
“You really hope that he sticks to the script, executes the trip as planned and avoids distractions, because the whole world is watching,” Mr. Hadley said.
Mr. Trump’s first trip is planned with that in mind. His travels will start in Saudi Arabia and Israel, where Mr. Trump’s counterparts are pleased to have him in office. He will have a brief but highly choreographed meeting with the pope. And his interactions with European allies in Belgium and Italy will keep the president away from the country’s most difficult adversaries.
Still, long trips are rarely error-free, and often presidents veer off the carefully constructed narrative for their trip.
President Bush once tried to leave after a news conference in Beijing, only to find the ornate door he was trying to go through locked. “I was trying to escape. Obviously, it didn’t work,” he joked later.
Mr. Bush’s father, President George Bush, threw up during a ceremonial dinner in Japan. And President Bill Clinton was caught during a trip in Senegal banging a bongo drum, strumming a guitar and chomping on a cigar — all in celebration of a judge’s decision throwing out a sexual harassment lawsuit.
Mr. Hadley said the first foreign trip for any president is especially a challenge, and perhaps more so for Mr. Trump, who has had little practice on the world stage and has often proved himself unwilling to stick to his prepared remarks.
But Mr. Hadley said Mr. Trump should not be underestimated.
“Remember, Trump is a nothing if not a showman,” Mr. Hadley said. “He’s been very public for decades and very conscious about how he comes across in the media. This is not a novice on stages.”