D.C. Mayor Muriel E. Bowser and President Trump were engaged in an escalating contest over control of Washington streets when the email from a military planner set off new alarms in the mayor’s office.

The official was seeking guidance Wednesday afternoon for the U.S. Northern Command in determining “route restrictions” for the “movement of tactical vehicles” and “military forces” from Fort Belvoir, Va., into the city to assist in “Civil Disturbance Operations.”

To Bowser’s aides, the request smacked of an imminent escalation in the federal force Trump had marshaled to quell the large street demonstrations over police brutality near the White House — the centerpiece of his bid to project the image of a strong leader who would establish “law and order” where local leaders had failed across the nation. Days earlier, Trump had falsely accused Bowser (D) in a tweet of refusing to allow D.C. police to assist in crowd control in Lafayette Square.

“The last time they asked us about that was in preparation to move tanks to the city for the Fourth of July” celebration last summer, said one D.C. government official, speaking on the condition of anonymity to discuss the private request. “We don’t want it to happen.”

A Defense Department official played down the email query as “due diligence” in case such forces are needed and said the vehicles in question are Humvees and personnel carrier trucks similar to those that already have been used in the city this week.

But the episode highlighted the escalating tensions and deepening distrust between Bowser and Trump, who has maintained a deep remove from local city life and has not established more than cursory relationships with city leaders.

In responding to the unrest, Bowser has generally deferred to the D.C. police department, which has more training and experience than other city police forces in managing large protests, which take place regularly in the nation’s capital. She has tried to balance support for peaceful demonstrators with a forceful denunciation of those who have looted businesses, whom she cast as outsiders even though most arrested are from the Washington region.

During a news conference Thursday, Bowser said she was alarmed by the growing presence of federal security authorities in the city and declared she wants federal “troops from out of state” kept out of the District. She also expressed concern that the Trump administration's move to extend security barriers beyond the White House perimeter to encircle Lafayette Square, closing it to the public, could become permanent.

“Keep in mind that’s the people’s house,” she said. “It’s a sad commentary that the [White] House and its inhabitants have to be walled off.”

The remarks were an amplification of her scathing reply to Trump’s false criticism about her performance days earlier. In a tweet of her own, Bowser mocked Trump — who had warned protesters of “vicious dogs” and “ominous weapons” guarding the White House — as hiding “behind his fence afraid/alone.”

“There is just a scared man,” she wrote of the president’s bluster.

Trump aides have fired back. On Fox News this week, White House press secretary Kayleigh McEnany criticized Bowser’s “befuddling actions,” citing the mayor’s decision to implement an 11 p.m. curfew on Sunday as “really not tough enough.” A fire had broken out at St. John’s Episcopal Church, a block from the White House, before the curfew began.

Bowser called for a 7 p.m. curfew on Monday and Tuesday.

“Unfortunately, the mayor did not provide early leadership to ensure peaceful protests and prevent riots and violence as demonstrated by the arson to St. Johns Church, defacing of national monuments, and destruction of several covid-19 testing sites in vulnerable communities, forcing the president to take necessary action to restore law and order,” White House spokesman Judd Deere said in a statement.

In recent days, the two have engaged in contrasting public appearances. The morning after the church fire, Bowser showed up at Lafayette Square to survey damage and speak to reporters; that evening, Trump strode through the park with senior aides after Attorney General William P. Barr ordered police to forcibly clear protesters with chemical gas and rubber bullets.

Trump posed for news photographs holding a Bible in front of the church, without going inside. Bowser, a practicing Catholic, joined protesters in prayer on Wednesday.

Trump’s increasingly fraught relationship with Bowser is emblematic of his eagerness to escalate political confrontations with Democratic state and local leaders, casting their jurisdictions as dangerous, dirty and poorly managed. But the tensions are amplified in the District by its unique status as a federal city whose local officials have long chafed over a lack of congressional representation and the federal government’s oversight of its spending decisions.

For decades, Republicans, including Trump, have opposed efforts to grant the city, which is majority Democratic, congressional voting rights. D.C. officials said Trump administration officials this week raised the prospect of a federal takeover of the city’s police department amid the protests, a move Bowser firmly opposed.

“The problem we have here . . . is, ‘Who is in charge?’ ” said Del. Eleanor Holmes Norton (D-D.C.).

Trump aides pointed to Bowser’s inclusion in calls the president has held with governors over the coronavirus pandemic and communication directly between the two in managing the outbreak as evidence of Trump’s cooperation with city leaders.

Until this week, Trump and Bowser maintained a cool but not overly strained relationship, at least by the standards of the combative president. Bowser visited him at Trump Tower in New York during the transition after his election in 2016, and a few months later, in March 2017, he asked her to brief him in the Oval Office about the city's preparations for a brewing snowstorm.

The meeting perplexed local officials, who said such conversations typically took place between city and federal management agencies, and the storm sprinkled a modest 2.5 inches on the city.

Bowser has largely refrained from publicly attacking the president beyond registering the usual Democratic objections to his actions — and Trump has not tagged her with a demeaning nickname, as he has with other political foils. She has focused her toughest criticism on matters directly involving the city, such as when the federal government did not fully reimburse the District government for the costs of providing security at Trump’s inauguration.

Before the unrest related to the death of George Floyd after he was arrested by Minneapolis police officers last week, their highest-profile clash came over Trump’s desire for a military parade in 2018.

Trump blamed “local politicians” for foiling his plans over high costs, which Bowser pegged at $21 million but the Pentagon put at $92 million. Bowser fired back with a tweet describing herself as “the local politician who finally got thru to the reality star in the White House” — a dust-up she touted on campaign mailers that fall as she cruised to reelection.

Unlike past presidents, Trump has not visited a city school or eaten at a local restaurant other than the steakhouse at the Trump International Hotel, a few blocks from the White House.

Before his photo op outside St. John’s this week, he had visited city churches five times, including three visits to St. John’s, according to Mark Knoller, a White House correspondents for CBS News Radio who keeps records of presidential outings. Former president Barack Obama, by comparison, visited D.C. churches 16 times in his first term, including nine visits to St. John’s.

On the weekends, Trump has regularly left town for his resorts in Florida, Virginia and New Jersey.

“You’ve got President Obama, who had a very close relationship with the city and would go to restaurants and take walks without tear gas and flash bombs outside the White House,” said Bo Shuff, executive director of D.C. Vote, which advocates for statehood. Yet Trump “is more financially invested in the city than any other president has been in the past based on the hotel.”

During Bowser’s news conference Thursday, a reporter expressed frustration trying to distinguish between federal and local police during the protests.

“I just hope that you take some of that frustration and channel it into coverage of D.C. statehood and why we need to be autonomous,” Bowser said. “I’m looking forward to that.”

Dan Lamothe contributed to this report.