But behind the scenes, there is as much fracture as focus. As America races to deploy next-generation wireless technology, several arms of the government are at odds over how to allocate space on the radio-frequency spectrum for 5G.

The Federal Communications Commission, which sets policy for spectrum licenses, has openly fought with the Commerce Department, which houses agencies that use spectrum for weather satellites that are crucial to predicting hurricanes. The departments of Transportation, Energy and Education have also objected to various plans to open up airwaves for faster networks. And amid all the fighting, a top Trump appointee responsible for mediating spectrum disputes abruptly quit this spring.

The resulting delays in spectrum allocation are no small matter, threatening to undermine America’s efforts to dominate the wireless technology that will be embedded in so many innovations in the future. 5G, short for fifth-generation wireless, is expected to be 100 times faster than today’s 4G networks. The country that takes the lead in 5G will pave the way for its companies to access more-powerful wireless technology sooner than foreign rivals. That means more profits and more jobs for the country that comes out ahead.

U.S. officials say the country is in position to reap those benefits. But the spectrum delays are part of the reason that China, where the national government is able to move with more unity, is seen by many as out in front in the 5G race. China has allotted vast swaths of spectrum for 5G, prompting warnings among U.S. officials that federal authorities need to move more quickly.

“We need the federal government to reduce its holdings of spectrum,” says FCC Commissioner Michael O’Rielly. “It’s a very big deal and it’s a very big problem.”

Mr. O’Rielly, who has been working to free up airwaves for years, says: “Everything I’ve worked on has taken twice as long as I thought.”

An eye on voters

There’s also plenty of political motivation for the Trump administration to resolve the spectrum squabbles. In early spring, Mr. Trump was shown two maps of the U.S., according to a person familiar with the exchange. One showed counties that voted for him in the 2016 election, while the other depicted areas underserved by broadband-internet providers.They looked identical, this person said.

The takeaway was simple: Improving internet access for rural voters could give the president a win with his voter base for 2020. If 5G lives up to its promises, engineers say it will not only enable a new generation of applications but also make home broadband more accessible and affordable in areas where internet access is spotty, slow and expensive, a goal both major political parties support.

But so far that hasn’t been enough to get everyone in the administration pulling in the same direction on the details of spectrum allocation, according to people familiar with the internal debates, or to spur a quick resolution of allocation issues that don’t involve such disagreements.

The wireless spectrum is divided into sections, or bands, each of which is used for different purposes—and several of which wireless companies want to access. One battleground is a section of spectrum known as the C-band. Wireless companies are clamoring for the FCC to make it available for 5G, but the agency needs to accommodate satellite companies that use it for beaming TV broadcasts.

The FCC has been reviewing the issue for more than two years, caught among several competing proposals. Satellite firms say the fastest solution is for them to run a private auction of the spectrum that they now use, overseen by regulators, that would allow 5G operators to quickly access the C-band. In return for handling the auction, the satellite firms would seek a cut of the billions of dollars the sale is expected to generate, though it’s not yet known how the proceeds of such an auction would be divided.

The Republican-led Senate Appropriations Committee has endorsed a different plan that the Senators believe would raise more money for the government. They’re calling for a public, FCC-run auction that wouldn’t rely on the satellite firms as middlemen. Many Democrats also favor a public auction, while there are some GOP lawmakers who say Congress should leave the decision to the FCC.

FCC Chairman Ajit Pai has said he wants to resolve the C-Band debate this fall. But this is just one of several disputes he is involved in over various bands of the wireless spectrum.

Supercharged speeds

On May 14, Mr. Pai announced another step to accommodate faster networks. The time has come, he said, to consider allowing Wi-Fi routers to operate across a wider swath of airwaves, supercharging their speeds. He pointed specifically to a band of radio frequencies measured at 5.9 gigahertz.

Faster Wi-Fi is a priority for the FCC because many of the future applications that will rely on the speed of 5G networks mayl also rely on the speed of Wi-Fi routers—for example, running a home full of connected devices.

But Mr. Pai’s remarks caused a stir at the Transportation Department. That piece of spectrum is currently earmarked for technology designed to allow vehicle-to-vehicle communications to avoid accidents—technology that automotive-industry advocates say will work in driverless vehicles but could also show up in cars people drive as soon as 2022. Ford Motor Co. and other auto makers say sharing the spectrum with Wi-Fi could interfere with those plans.

One day after his speech, Mr. Pai spoke by phone with Transportation Secretary Elaine Chao, according to people familiar with the discussion. The cabinet secretary asked Mr. Pai to delay the review of Wi-Fi spectrum and he agreed, according to these people. A Transportation Department spokesman says: “As the Department is firmly committed to advancing public safety, it believes it would be premature to make any spectrum allocation decisions” before completing more tests.

Six months later, the agencies are still talking and a proposal from Mr. Pai hasn’t materialized. And the longer this and other spectrum disputes drag on, experts say, the more difficult it will be to compete with the Chinese.

Separately, the Departments of Energy and Education have objected to opening up spectrum bands used by utilities and schools, respectively.

The Department of Energy has asked the FCC to reconsider a proposed opening up of the 6 gigahertz band, which is currently used by utility companies. The Wi-Fi industry wants access to this band as well as the neighboring 5.9 gigahertz band. A senior DOE official wrote to the FCC in September asking the commission to look for spectrum bands elsewhere, or to carve out some spectrum specifically for utilities, calling a technology that could be used to share the spectrum “neither field-tested nor verified.”

In July, the FCC voted to rewrite the rules governing spectrum frequencies around 2.5 gigahertz, which have historically been used by educational institutions. The Department of Education wrote the FCC a letter opposing the move and asking for a delay to examine its impact, warning against “a failure to meet the needs of students.”

A mediator resigns

The U.S. long ago created an agency to help resolve such interagency spats: the National Telecommunications and Information Administration, or NTIA, a part of the Commerce Department.

But when Mr. Pai and Ms. Chao had their phone call, the NTIA wasn’t on the line. The head of that agency, David Redl, had just quit.

Mr. Redl was at the center of a disagreement over yet another band of wireless spectrum related to 5G—the high-frequency “millimeter wave” band. Different portions of the spectrum are particularly well suited for different uses, and the millimeter wave band is ideal for high-capacity, superfast wireless service in cities. The FCC has been auctioning these airwaves, with wireless carriers committing billions of dollars for the rights to use that spectrum in 5G networks.

Two agencies have raised concerns—the National Oceanic and Atmospheric Administration and the National Aeronautics and Space Administration, both part of the Commerce Department. Their scientists use satellites that pick up high-frequency signals to help predict the weather, and they worry that interference from 5G networks could make forecasts less accurate. They want significant limits placed on 5G operators in this band of spectrum.

Mr. Pai, citing the FCC’s experts, has argued that those concerns aren’t justified and that the Commerce Department scientists’ desired limits would make the spectrum useless for 5G.

Tensions boiled over early this year, when U.S. officials were meeting with other countries for discussions on harmonizing the way spectrum is used across the globe. Commerce Department officials told representatives of other countries that the FCC wasn’t speaking for all of the U.S. government, infuriating FCC officials who felt the U.S. had agreed on a position, according to people familiar with the matter. A Commerce Department spokeswoman said the agency “isn’t aware of this event.”

Mr. Pai’s appeals to the White House, meanwhile, at times had the effect of sidelining the Commerce Department. In April, Mr. Pai met Mr. Trump and others at the White House and the president suggested holding a public 5G event, according to a person familiar with the discussion. FCC staff quickly helped organize the gathering with the tower climbers in the Roosevelt Room. Mr. Pai spoke, but Commerce Department officials weren’t invited and learned about the event secondhand, according to people familiar with the matter.

Mr. Redl, the NTIA administrator, tried to mediate the dispute. He clashed with Earl Comstock, a senior aide to Commerce Secretary Wilbur Ross, according to people familiar with the two men’s views. Mr. Comstock has told others the government shouldn’t be giving out more spectrum for commercial use, even if 5G is the goal, these people said.

This spring, Mr. Comstock discussed removing Mr. Redl with the White House Presidential Personnel Office, according to people familiar with the matter.

On May 6, Mr. Redl gave a speech calling for more cooperation on spectrum, warning against “false choices that will shortchange America.” He resigned on May 9. He was under pressure from senior Commerce Department officials to step down, people familiar with the matter said. Mr. Redl declined to discuss the circumstances of his departure for this article.

A Commerce Department spokeswoman denied that Mr. Comstock sought backing from the White House to fire Mr. Redl or that Mr. Ross pressed Mr. Redl to step down. She said Messrs. Comstock and Redl “were on the same page” regarding millimeter-wave spectrum and “worked together to support other DOC staff in the interagency process.”

The debate escalated after Mr. Redl left. Mr. Pai at a Senate hearing called Commerce Department research on the interaction between 5G networks and weather satellites “so flawed as to make the study, in our view at least, meaningless.” Sen. Ron Johnson (R., Wis.), an ally of Mr. Pai, wrote a public letter that accused Mr. Comstock of “placing personal animosity ahead of our country’s 5G goals”.

Mr. Ross disputed that, shooting back in his own letter: “Just because the FCC does not agree with the results of the NOAA/NASA analyses does not mean the science is ‘fundamentally flawed.’ ”

Still waiting

On July 11, officials from the FCC, Commerce Department and other agencies met in the White House Situation Room. White House National Economic Council Director Larry Kudlow reminded Mr. Ross of the president’s desire for 5G deployment, according to people familiar with the matter. Mr. Ross, speaking from prepared talking points, voiced the concerns of the Commerce Department’s scientists, these people said.

The following week, the group gathered again—this time without staff. Mr. Ross reprised his concerns, but other senior officials including Mr. Kudlow and acting White House chief of staff Mick Mulvaney made clear the president was backing Mr. Pai, who left the meeting feeling vindicated, according to people familiar with the matter.

“We’ve had some internal squabbles, as one might expect, and they are already all solved,” a senior White House official said in an interview. The U.S. is in “great shape” on 5G deployment, the official said, adding: “It’s a miracle we are moving as fast as we’re doing.”

Since the July meetings, officials say they have settled on a compromise for the rules governing millimeter-wave spectrum. International discussions over such rules are continuing this month at a summit in Egypt.

“While a lot of effort has been wasted dealing with unnecessary problems, so far we’ve been able to overcome them,” an FCC spokesman says, noting that planned spectrum auctions are still on schedule.

In the meantime, though, fighting has broken out on a new front: the National Spectrum Strategy, a document commissioned by Mr. Trump in October 2018 that will lay out the U.S. strategy for making spectrum available for 5G and other advanced technologies.

Drafts of the policy paper are circulating privately, but officials have argued over details including how the document would describe the need for government agencies to clear the path to a 5G network, according to people familiar with the discussions.

Tom Wheeler, a former FCC chairman who served during the Obama administration, said the lack of marching orders from the top makes it harder for federal agencies to settle disputes. He also said vacancies in key political positions have slowed down the government’s work.

The Commerce Department spokeswoman said that despite Mr. Redl’s departure, the administration “has strong leadership and a well-seasoned staff in place working on spectrum policy.” She said Mr. Ross sent the spectrum strategy document to the White House “over a month ago.”

The National Spectrum Strategy was due this summer. It still hasn’t been released.

Messrs. Tracy and FitzGerald are Wall Street Journal reporters based in Washington. They can be reached at ryan.tracy@wsj.com. and andrew.fitzgerald@wsj.com.