Donald Trump’s advisers are considering whether to modify his travel after threats to his life from Iran and two assassination attempts, according to several people briefed on the matter, a shift that could affect the way the Republican nominee campaigns in the race’s final stretch.

Among the discussions are what events can be secured, as well as the possibility that he might travel less on his own Trump-branded plane, according to two of the people briefed on the discussions.

Secret Service officials had previously suggested to Mr. Trump’s team that it consider additional changes to his travel plans and campaign routines, after two assassination attempts against him in roughly two months.

Mr. Trump and his team are also facing an assassination threat from Iran as revenge for ordering the killing of the Iranian general Qassim Suleimani in early 2020, while Iran also has led hacking attempts on campaign officials’ emails. Two federal intelligence officials briefed Mr. Trump on Tuesday about the threats from Iran, his campaign said. An official with the Office of the Director of National Intelligence, an umbrella entity that helps coordinate the work of the nation’s intelligence agencies, acknowledged the briefing but declined on Tuesday and Wednesday to comment on the substance.

A spokesman for the National Security Council, Sean Savett, condemned Iran for its threats and said the government treated it as “a national and homeland security matter of the highest priority.” He said the government had “warned Iran publicly and privately to stop this activity or face severe consequences.”

As an example of what some travel could look like, the Trump team used multiple planes to get the candidate and his team to an event site in North Carolina on Wednesday, according to a person briefed on the matter.

A Secret Service spokesman did not immediately respond to a request for comment Wednesday.

Mr. Trump has always been a challenging figure for officials to protect compared with previous presidents, both when he was in office and since he left. He owns multiple properties, is set in his ways and doesn’t like to change his routine, and he is happiest when he’s greeting people on the patios of his clubs. Now, his aides have been forced to consider adjusting his travel schedule. They were advised that at least one event couldn’t be adequately secured in time for a planned visit. And he has told advisers he is not planning to play golf — his main source of relaxation — at his courses.

The most recent assassination attempt occurred at the Trump International Golf Club in West Palm Beach, Fla., on Sept. 15. Ryan W. Routh, 58, of Hawaii, had staked out Mr. Trump’s golf course and hid inside shrubs on the perimeter of the course as he waited for Mr. Trump to get within range of his semiautomatic rifle, the authorities said. A Secret Service agent, scouting the course ahead of Mr. Trump, spotted the barrel of Mr. Routh’s gun in the bushes and started firing at him. Mr. Routh ran from the golf course and tried to escape in his car before police caught him 45 minutes later on a highway. He faces two firearm charges but federal prosecutors plan to pursue a charge of attempted assassination.

Steven Cheung, a Trump campaign spokesman, declined to address specific questions about the campaign’s planning in response to threats, and instead blamed Democrats generally and Vice President Kamala Harris specifically for rhetoric that he said has been “emboldening” people seeking to harm Mr. Trump.

The former president and current Republican presidential nominee prides himself on his plane. It has his name emblazoned on it in gold — his advisers refer to it as Trump Force One — and he wanted to keep using it as president after the 2016 election, something that the Secret Service did not support. He has also used his plane as a political backdrop, flying in to appear at rallies within view of crowds or using it behind him at airplane-hangar events, a projection of power to rival Air Force One.

But privately owned planes like Mr. Trump’s — a refurbished Boeing 757 that Mr. Trump bought from the billionaire Paul Allen two decades ago — are not equipped with the kind of protections that Air Force One has.

Using other private planes could add hundreds of thousands of dollars to the campaign’s spending. And Mr. Trump’s advisers have devoted a significant amount of time and energy dealing with security arrangements, three people briefed on the matter said.

Mr. Trump’s team has dealt with other threats that have disrupted recent trips.

On at least one campaign stop, a drone was spotted flying over Mr. Trump’s motorcade. The Secret Service scrambled the motorcade cars in different directions to create confusion about which car Mr. Trump was riding in, according to two people briefed on the discussions. And a planned visit to a Polish shrine in Pennsylvania last Sunday was canceled partly for security reasons, three people briefed on the matter said.

Mr. Trump addressed the Iranian threats on his social media website on Wednesday. “Moves were already made by Iran that didn’t work out, but they will try again,” Mr. Trump wrote on Truth Social, shortly after midnight. “Not a good situation for anyone. I am surrounded by more men, guns, and weapons than I have ever seen before.”

In private discussions with his associates, Mr. Trump has repeatedly questioned why the Biden administration isn’t doing more to publicly denounce the threats he’s facing and to put Iran on notice, according to two people with knowledge of his remarks.

“If this was Kamala or another Democrat, we’d blow up Iran,” one of those people, who spoke on the condition of anonymity, recalled Mr. Trump saying. “They won’t do anything because it’s me.”

Some in Mr. Trump’s circle spoke of then-President Bill Clinton ordering Tomahawk cruise missiles fired on Iraqi intelligence headquarters in Baghdad after a foiled assassination attempt on Mr. Clinton’s predecessor, George H.W. Bush.

Mr. Trump made a version of that statement on Wednesday at an event in Mint Hill, N.C., suggesting that the current administration should warn foreign leaders threatening Mr. Trump that if they harm him, they’ll be blown “to smithereens.

“And there would be no more threats,” Mr. Trump said, adding, “Right now we don’t have that leadership or the necessary leaders.” He pointed out that the president of Iran is in the United States for the United Nations General Assembly, being guarded by law enforcement officials, while he, the former president, remains under threat, describing it as a strange set of circumstances.

Mr. Trump has told aides that he “can’t think about” the threats. Yet he has shown occasional signs that the assassination attempts are getting to him. At a rally on Long Island last week, he was visibly startled when he thought he saw someone approaching the stage as he spoke. He acknowledged, chuckling, that he has a “yip problem,” referring to his nerves.

Mr. Trump has vented to aides that the threats he’s facing and the enhanced security they require constitute a form of “foreign election interference” meant to prevent him from campaigning.

And while Mr. Trump and his team are supportive — and protective — of the former president’s own Secret Service detail, they have been concerned with the agency’s headquarters and whether agency leadership had previously approved a sufficient level of protection for him. Tensions between the Trump campaign and the Secret Service deepened significantly after the near-miss shooting in Butler, Pa., on July 13.

In his social media post, Mr. Trump praised Congress for its recent bipartisan vote to approve extra funds for the Secret Service. “Nice to see Republicans and Democrats get together on something,” he wrote. “An attack on a former President is a Death Wish for the attacker!”

There remains a persistent concern among Mr. Trump’s advisers about whether the two would-be assassins — Mr. Routh and Thomas Crooks, who was killed by law enforcement officials moments after firing at Mr. Trump in Butler — have ties to foreign governments. At his North Carolina event on Wednesday, Mr. Trump suggested the two assassination attempts might be tied to Iran. So far, there is no evidence that either Mr. Routh or Mr. Crooks was working on behalf of a foreign nation.

A third man, a Pakistani national, Asif Merchant, who has ties to Iran, has pleaded not guilty to federal charges that he was part of a murder-for-hire plot to assassinate Mr. Trump.

Mr. Trump continues to want to hold large-scale, high-profile events, including a rally at Madison Square Garden tentatively planned for late October. He also has announced a return on Oct. 5 to Butler, where his ear was grazed by what the F.B.I. later said was a bullet or bullet fragments.

The University of Alabama has confirmed that Mr. Trump plans to attend a major football game in Tuscaloosa on Saturday against the University of Georgia. The stadium can hold a crowd of roughly 100,000.

“The safety of our campus is and will remain our top priority,” the university said in a statement, adding that the university police “will work closely with the U.S. Secret Service and other law enforcement partners to coordinate security.”

The change in security protocols is a far cry from Mr. Trump’s earliest days as a third-time candidate, when access to his private club and residence, Mar-a-Lago, was freewheeling and people could sometimes walk in with virtually no screening.

These days, the protocols are significantly more enhanced.

At an event on Tuesday in Savannah, Ga., Mr. Trump recounted the recent assassination attempt, and then told the audience, “My profession is a very dangerous one.”

As a point of comparison, he cited the death rates of race-car drivers and bull riders as “one-tenth of 1 percent.”

“Presidents?” he said. “I don’t want to tell you the percentage. But it happens to be a very dangerous profession.”