On Monday in France, President Trump announced he was likely to hold next year’s Group of Seven summit — an event involving seven world leaders, hundreds of diplomats, and a huge police presence — at his own golf resort in Doral, Fla.

Back in Doral, Police Chief Hernan Organvidez was caught by surprise.

If the summit came to the city, Organvidez would be a crucial part of preparations — trying to turn a sprawling golf course surrounded by houses, busy streets and a nearby airport into a walled-off diplomatic island. But nobody has told him he needs to make such plans.

Organvidez said that after hearing Trump’s remarks, he called the head of the local Secret Service office.

“He said, ‘Miami’s being considered, but we don’t know exactly what’s going to happen,’ ” Organvidez said. The police chief asked: Who would pay for the preparations? When would it happen? No answers.

“I have rumors,” Organvidez said, but nothing else. Without more information, he asked, “how am I going to deal with such a big event?”

Trump’s promotion of Doral as the best site for the international summit has renewed criticism that he is using his office to generate revenue for his private business — and in this case, in possible violation of a constitutional ban on presidents accepting foreign payments.

The president’s abrupt announcement also raised questions about how Doral would handle the logistical challenges of such an enormous undertaking — and what preparations, if any, are underway.

Officials in South Florida said they’d been given no orders to plan — even in a preliminary way — for hosting the summit.

“We have nothing. We have no official communication with anybody,” said Patty Hurtado de Mendoza, a spokeswoman for Miami-Dade County Mayor Carlos A. Giménez.

The Trump Organization did not respond to questions.

In recent years, U.S. officials chose isolated sites for the confab: Camp David, the presidential retreat in Maryland; and Sea Island, off the coast of Georgia.

If Trump taps Doral, officials would have to create the same secure cordon on a far more complicated site: a patchwork of office parks near the Miami airport, with busy roads on all sides.

“Nuts,” said Robert Goodwin, a George W. Bush appointee who ran the 2004 Group of Eight summit at Sea Island, said of the idea of a Doral summit.

“It’s possible, sure. Anything’s possible. But it doesn’t make too much sense” to do it at Doral, Goodwin said.

At the Sea Island summit, he said, organizers sealed off the island, transported world leaders in by helicopter and used Navy ships and advanced radar planes to patrol the seas nearby. A no-fly zone shut down the airspace above.

That was easier, Goodwin said, because they had an island.

Considering Doral for the summit’s location “is just crazy,” he said. He said the busy Miami airport might be affected and that organizers would have to scour nearby neighborhoods for people seeking to launch a rocket or other airborne attack. “It would be a nightmare to secure,” he said.

The location of the G-7 summit, for which hosting duties rotate among the member countries, is at the president’s discretion when it is held in the United States.

White House spokeswoman Stephanie Grisham said Tuesday that Doral is among several potential sites being considered and that a date for the event has not been selected.

But Trump himself continued to promote the resort, taking to Twitter to blame “Radical Left Democrats” for spreading a “false and nasty rumor” about a bedbug infestation at Doral. (In 2017, the Trump Organization settled a lawsuit by a Doral guest who said he had been bitten multiple times by bedbugs while staying in the luxe Jack Nicklaus Villa at Trump’s property.)

“No bedbugs at Doral,” the president tweeted.

On Tuesday, the State Department said that the White House had sent teams to multiple sites to see if they would be suitable to host the summit.

The teams looked at “major airports, security arrangements, accommodation availability and major world events happening that same year,” a State Department official said in a statement.

Grisham said the potential sites are in California, Colorado, Florida, Hawaii, Michigan, North Carolina, Tennessee and Utah, along with the District.

She said the administration is using much the same criteria as past administrations did in choosing a location, including the type and size of accommodations and meeting rooms, other hotel space within a 100-mile radius, proximity of airports and medical facilities, and things for spouses to see and do.

Trump said that search had led them to favor his own 643-room golf resort, which has struggled with declining revenue and profit in recent years. “It’s, like, such a natural,” the president said Monday, praising the club’s ample parking and proximity to the Miami airport.

Former U.S. officials involved in planning summits said that Trump’s club did have some things going for it. It has eight villas — essentially, separate wings of hotel rooms — that could allow each country delegation to have its own space. There would be no bodyguards jostling for the same elevators.

“That’s not a bad physical plant. Because, obviously, there’s a central building where you could have the meetings. And then each nation could get one” villa, said Pat Kennedy, a longtime State Department employee who helped plan multiple summits and retired in 2017.

“As a logistician, this does not bother me,” Kennedy said.

Kennedy said that the State Department funds many of the expenditures of a summit, including rooms for U.S. personnel and foreign leaders. He said foreign countries pay for rooms for their staff.

Trump is facing a lawsuit filed by congressional Democrats for allegedly violating the Constitution’s ban on emoluments, or payments from foreign states.

Trump has said he does not think he would profit if the event is held at Doral.

“I don’t want to make money,” he said Monday. His company has said it donates all profits from foreign-government business to the U.S. Treasury but does not detail how it calculates that profit.

In 2004, the company that owns the Sea Island resort netted about $2.5 million from its contract with the State Department to host the international summit that year, according to Goodwin.

The company declined to comment.

Kennedy, who worked on summits going back to the 1980s, said it was hard to project what Trump’s profit would be. The United States has never tried to house all the top dignitaries at a single hotel before, he noted.

Kennedy also noted that while foreign leaders may demand better suites than what the Doral club offers now, the U.S. government would not cover those costs. “We don’t pay for cosmetic improvements,” Kennedy said.

Former Secret Service personnel said that, for their purposes, the downside of Doral is that it has thousands of residents living nearby. That might require disruptive screening of people going to and from their homes.

But they said that the Secret Service already protects a far larger annual gathering of world leaders, in a far denser place: New York, during the annual meeting of the U.N. General Assembly.

“At the end of the day, the Secret Service will make anything work,” said Jonathan Wackrow, a security-risk consultant and former lead agent on President Barack Obama’s detail. “From a security standpoint, I think the security concerns are de minimis. . . . The major impact is to the whole surrounding area. Everything outside Doral becomes road closures.”

In South Florida, that possibility left officials worried — especially because they weren’t even sure when the summit might be.

“If it happens somewhere else, God bless ’em,” said Organvidez, the Doral police chief. “If it happens here, God bless me.”

Mike DeBonis, Carol D. Leonnig, Joshua Partlow and John Wagner contributed to this report.