President Trump offered only a vague policy response on Thursday to the killing of George Floyd, saying he would sign an executive order encouraging better practices by police departments while rejecting more far-reaching proposals to tackle racial injustice and police brutality in the United States.

Dismissing police misconduct as the work of only a few “bad apples,” Mr. Trump strongly defended law enforcement agencies and made clear he had little interest in broader legislation being debated in Congress. At a round-table discussion he convened in a Dallas church before hosting a campaign fund-raiser, the president derided activists calling for defunding or dismantling police departments.

“Instead, we have to go the opposite way,” Mr. Trump said. “We must invest more energy and resources in police training and recruiting and community engagement. We have to respect our police — we have to take care of our police. They’re protecting us, and if they’re allowed to do their job, they’ll do a great job. You always have a bad apple no matter where you go. You have bad apples. There are not too many of them, and I can tell you there are not too many of them in the police department.”

The president’s staunch defense of the police came as city, state and federal lawmakers in both parties were working to develop sweeping proposals to change the way policing works in the United States. Mr. Trump was more explicit in what he would not back than what he would, beyond repeating his support for expanding economic development, investing in medical facilities and encouraging school choice in minority communities.

He said, without elaborating, that the executive order being drafted would encourage police departments “to meet the most current professional standards for the use of force.”

And while he called the killing of Mr. Floyd “a disgrace,” the president referred to it only in passing and instead castigated critics who have said law enforcement is afflicted with systemic racism that needs to be addressed.

“We have to work together to confront bigotry and prejudice wherever they appear, but we’ll make no progress and heal no wounds by falsely labeling tens of millions of decent Americans as racists or bigots,” Mr. Trump said. “We have to get everybody together. We have to be in the same path.”

Campaigning on Thursday in Pennsylvania, former Vice President Joseph R. Biden Jr., the presumptive Democratic presidential nominee, criticized Mr. Trump for sowing division in the country. Mr. Trump, he said, had “decided that he was going to pit us against one another based on race,” recalling the president’s comments after a white nationalist rally in 2017 in Charlottesville, Va.

“When a president speaks, no matter how good or bad he is, people listen,” Mr. Biden said at a round table of his own. He said that when Mr. Trump “speaks and gives credibility” to racist people, “they come out from under the rocks.”

“And you’re seeing it,” he added. “You’re seeing it all across the country.”

The former vice president said the killing of Mr. Floyd had a larger effect globally than the assassination of the Rev. Dr. Martin Luther King Jr. did in 1968. “Even Dr. King’s assassination did not have the worldwide impact that George Floyd’s death did,” Mr. Biden said at his event, where he rolled out a new eight-part plan to reopen the economy after months of lockdown because of the coronavirus pandemic.

Mr. Biden, speaking in West Philadelphia in a room that was the original home of “American Bandstand,” noted that the prevalence today of cellphones that can record episodes of police misconduct had “changed the way everybody’s looking at this.”

“Look at the millions of people marching around the world,” Mr. Biden said, a face mask dangling from his left ear. “So my point is that I think people are really realizing that this is a battle for the soul of America. Who are we? What do we want to be? How do we see ourselves? What do we think we should be? Character is on the ballot here.”

Mr. Biden met with Mr. Floyd’s family in Houston this week and recorded a video message for his funeral. He has called for “real police reform” and has emphasized the need to address systemic racism in society.

Mr. Trump’s trip to Dallas came as he resumed campaigning after a monthslong suspension forced by the virus. The president trails Mr. Biden both nationally and in key swing states. Even in Texas, a Republican bulwark for decades, a half-dozen surveys since April show the Democrat in striking distance with the incumbent. A Quinnipiac University poll released last week showed Mr. Trump with 44 percent and Mr. Biden with 43 percent, and a Public Policy Polling survey showed a tie at 48 percent.

In addition to a possible battleground, Texas is seeing its coronavirus infections on the rise after the reopening of businesses and public life. Three of the 10 counties in the United States with the highest number of new cases per resident in the past two weeks are in Texas: Jones, Moore and Walker. Even as Mr. Trump visited, Dallas County reported 312 new cases on Thursday, its highest number yet and the third straight day of a record.

Mr. Trump brought with him not only Attorney General William P. Barr but also two of the only prominent black members of his administration — Ben Carson, the secretary of housing and urban development, and Dr. Jerome M. Adams, the surgeon general.

Meeting with police union leaders and religious leaders at Gateway Church, Mr. Trump did not invite any of the top three law enforcement officials in Dallas, all of them African-American, according to The Dallas Morning News. Not included in the event were Chief U. Reneé Hall of the Dallas Police Department, Sheriff Marian Brown or District Attorney John Creuzot.

Mr. Trump did invite Vernell E. Dooley — the police chief of Glenn Heights, a town of about 11,000 south of Dallas — who is African-American — and he praised the president’s efforts on Thursday.

As Mr. Trump prepared to fly to Dallas on Thursday, Chief Hall’s department posted a Twitter message that said, “Let’s work together to end racism,” and included a video showing police officers kneeling with and hugging protesters, with the caption “Because Black lives do matter.”

After his fund-raiser, where donors paid $580,600 each for a meal and a photograph, Mr. Trump will fly to New Jersey for a long weekend at his Bedminster golf club. On June 19, he plans to hold his first campaign rally in months in Tulsa, Okla.

Zach Montague contributed reporting.