Joseph R. Biden Jr. on Friday released his plan for reopening classrooms amid the coronavirus crisis, emphasizing both deference to local decision-making and federal assistance to schools, and setting up yet another sharp contrast with President Trump, who has insisted that schools should rapidly resume in-person classes.

The question of when and how schools should reopen this fall has been a source of anguish and uncertainty for parents, students and educators. They are concerned about the health risks of full classrooms as the pandemic rages on, but are also often struggling with the professional and personal challenges posed by remote learning. Research shows that remote learning is problematic for most students, and is especially damaging for low-income and other vulnerable students.

Mr. Trump has favored a hard-line position — objecting to federal experts’ advice while calling for schools to fully reopen — over a more nuanced approach, pursuing a pressure campaign in service of his demand.

In a statement and accompanying video, Mr. Biden delivered both direct and implicit rebukes of his opponent’s posture as he unveiled a five-point “road-map” on the issue. Also Friday, Mr. Biden, the presumptive Democratic nominee, said at a fund-raiser that he had begun receiving intelligence briefings. He warned that “the Russians are still engaged in trying to delegitimize our electoral process” and that “China and others are engaged as well in activities that are designed for us to lose confidence in the outcome.” Those remarks came several hours after he released the school reopening plan.

“Forcing educators and students back into a classroom in areas where the infection rate is going up or remaining very high is just plain dangerous,” Mr. Biden said in the video, even as he acknowledged the challenges families are confronting.

A statement from his campaign said that Mr. Biden “believes that the decision about when to reopen safely should be made by state, tribal and local officials, based on science and in consultation with communities and tribal governments. It should be made with the safety of students and educators in mind.”

The education secretary, Betsy DeVos, whose instinct in office has been to defer to local and parental control, has urged that schools follow the White House’s push to reopen.

Mr. Biden recommended that federal agencies establish a set of national guidelines to aid school reopening decisions.

“The Trump administration’s chaotic and politicized response has left school districts to improvise a thousand hard decisions on their own,” his proposal read. “Schools need clear, consistent, effective national guidelines, not mixed messages and political ultimatums.”

He called for emergency funding for public schools and child care providers — about $30 billion for school districts is needed, he suggested, and another $4 billion for upgraded technology and broadband. He also urged a “large-scale U.S. Department of Education” effort to improve remote learning and smooth the reopening process.

Jill Biden, an English professor who taught at a community college throughout her husband’s time as vice president, has helped roll out Mr. Biden’s education policies and is often a surrogate for him at education-related events. She appeared with Mr. Biden in the video to announce the plan and detail some educators’ concerns. She acknowledged the hardships facing students, families and teachers who desperately want to return to the classroom, nodding to families who are struggling to balance work and child care.

But, she said, “it’s wrong to endanger educators and students. We need a better plan.”

In his proposal, Mr. Biden also recommended initiatives designed to close what his campaign described as “systemic racial and socioeconomic disparities in education” that have worsened during the pandemic.

“Everyone wants our schools to reopen,” Mr. Biden said in the video. “The question is how to make it safe, how to make it stick.”

The first step, Mr. Biden said, was reducing coronavirus cases.