WASHINGTON >> President Donald Trump berated his own Cabinet officers Thursday for not prosecuting or implicating his political enemies, lashing out even as he announced that he planned to return to the campaign trail Saturday just nine days after he tested positive for the coronavirus.

In his first extended public comments since learning he had the virus last week, Trump went on the offensive not only against his challenger, former Vice President Joe Biden, but the Democratic running mate, Sen. Kamala Harris, whom he called “a monster” and a “communist.”

He balked at participating in the his debate next Thursday with Biden if held remotely as the organizers decided to do out of health concerns.

But Trump secured a statement from the White House physician clearing him to return to public engagement Saturday and then promptly said he would hold a campaign rally in Florida, two days earlier than the doctor had originally said was needed to determine whether he was truly out of danger. The president again dismissed the virus, saying, “when you catch it, you get better,” ignoring the more than 212,000 who have died from it in the United States.

Dr. Sean P. Conley, the White House physician, reported that Trump “has responded extremely well to treatment” and that by Saturday, “I fully expect the president’s return to public engagement.” Conley, who has previously acknowledged providing a rosy view of the president’s condition to satisfy his patient, contradicted his own timeline offered when Trump was released from the hospital, when he said doctors wanted to “get through to Monday.”

Trump has not been seen in person since returning from the hospital Monday, but he sought to reassert himself on the public stage with a pair of telephone interviews with Fox News and Fox Business, a video and a series of Twitter messages. Even for him, they were scattershot performances, ones that advisers said reflected increasing frustration over his political fortunes only 26 days before an election with surveys that show him trailing Biden by double digits.

The president castigated his own team, declaring that Attorney General William Barr would go down in history “as a very sad, sad situation” if he did not indict Democrats like Biden and former President Barack Obama. He complained that Secretary of State Mike Pompeo had not released Hillary Clinton’s emails, saying, “I’m not happy about him for that reason.” And he targeted Christopher A. Wray, the FBI director. “He’s been disappointing,” Trump said.

He was all over the map, throwing out unsubstantiated or discredited accusations, explaining that he wanted to bring home troops from Afghanistan to be ready to fight China or Russia if necessary and calling Gov. Gretchen Whitmer of Michigan “the lockup queen” even as his own Justice Department was announcing the existence of an anti-government group’s plot to kidnap her.

As for his opponents, he said that Biden “wouldn’t be president for two months” because “he’s not mentally capable,” leaving Harris to then take over the presidency. “She’s a communist,” he said. “We’re going to have a communist.” A few hours later, Trump reposted Twitter messages claiming that Speaker Nancy Pelosi might be orchestrating “a coup” against him.

But it was his assault on his own appointees that hinted at the escalating imperative to change the course of a campaign that has defied his efforts to shape it for months, what amounted to a plea for an October surprise.

“Unless Bill Barr indicts these people for crimes, the greatest political crime in the history of our country, then we’re going to get little satisfaction unless I win and we’ll just have to go, because I won’t forget it,” Trump said, referring to the investigation into his 2016 campaign ties with Russia. “But these people should be indicted. This was the greatest political crime in the history of our country, and that includes Obama and it includes Biden.”

Trump has often argued that his political antagonists should be prosecuted, but in this case, he went further by indicating that he had directly pressured Barr to indict without waiting for more evidence. “He’s got all the information he needs,” the president said. “They want to get more, more, more, they keep getting more. I said, ‘You don’t need any more.’”

Even as he sought to reassert himself on the public stage after a week in the hospital and the White House infected with the coronavirus, Trump seemed to suggest he may have been infected by the Gold Star parents of soldiers killed in battle at an event honoring them last month at the White House, although a spokesman later denied he meant that.

Fellow Republicans exhibited increasing frustration with the president’s casual approach to the virus that has now infected not just himself and the first lady but two dozen other high-ranking officials, campaign aides, advisers and Republican senators who attended White House events. Sen. Mitch McConnell of Kentucky, the majority leader, even indicated that he was boycotting the White House because of its lax handling of the virus.

Pelosi said she planned to introduce legislation Friday creating a commission on presidential capacity to review the health of a commander in chief under provisions of the 25th Amendment providing for the temporary transfer of power to the vice president in case of inability to discharge the duties of the office. “Crazy Nancy is the one who should be under observation,” Trump replied on Twitter.

The president’s phone interview with Maria Bartiromo of Fox Business was his first time answering questions since he was infected with the virus and flown to the Walter Reed National Military Medical Center, where he stayed for three nights. He insisted that he had recovered and was no longer taking the experimental drugs used to treat the virus, but that he was still taking a steroid that doctors say can produce bursts of energy, euphoria and even a sense of invulnerability.

“I felt pretty lousy,” Trump said. But, he added, “I’m back because I’m a perfect physical specimen and I’m extremely young.” He once again played down the severity of the disease. “Now what happens is you get better,” he said. “That’s what happens, you get better.”

Trump later released a video addressed specifically to senior citizens, who were once his political base but have increasingly soured on him as they have been disproportionately affected by the pandemic, according to polls.

“To my favorite people in the world, the seniors,” he said in the video. “I’m a senior. I know you don’t know that. Nobody knows that. Maybe you don’t have to tell them. But I’m a senior.”

Acknowledging that he had been “very sick,” he praised the experimental treatments he was given for the virus and vowed to provide them to seniors. “I want you to get the same care that I got,” he said. “You’re going to get the same medicine. You’re going to get it free, no charge, and we’re going to get it to you soon.”

White House aides privately expressed concern about whether the president’s animated mood in recent days stemmed from the dexamethasone steroid he is on. Doctors not involved with the president’s care said it could have a significant effect on a patient’s behavior.

Dr. Negin Hajizadeh, a pulmonary/critical care physician at Northwell Health, noted that the majority of COVID patients receiving dexamethasone are on mechanical ventilation and in a state of induced coma, so they do not exhibit any behavioral side effects. But, she said, large studies show that generally 28-30% of patients will exhibit mild to moderate psychiatric side effects like anxiety, insomnia, mania or delirium after receiving steroid treatments, and about 6% may develop psychosis.

“When we prescribe steroids we warn our patients: ‘This may cause you to feel jittery, might cause you to feel irritable,’” Hajizadeh said. “We will tell family members, especially for our older patients, ‘This may cause insomnia, this may cause changes in eating habits and, in extreme cases, mania and impaired decision making.’ “

Watching the news coverage and angry at the state of the race, Trump has been imploring aides to let him resume campaign rallies as soon as this weekend, which now could be possible. He showed up again in the Oval Office on Thursday despite efforts to get him to remain in the residence until he was more fully recovered.

Around the White House and inside the Trump campaign, some advisers are worried. Others are looking at the calendar and arguing that there is still a lot of time left while they realize there are few if any opportunities to change the trajectory of the race. That would be especially true without next week’s debate.

Alex Conant, a Republican strategist and former aide to Sen. Marco Rubio of Florida, said that the Trump campaign was entering a dangerous window, suggesting that a campaign heading for a possible defeat becomes treacherous.

“The knives come out, the donors flee and the candidate throws embarrassing Hail Marys,” he said. “Most politicians can handle losing a race, but they really don’t want to be embarrassed. When a loss seems inevitable, people who want a future in politics start looking out for their own interests. People start looking over their shoulders.”