Joseph R. Biden Jr., the Democratic presidential nominee, said on Tuesday night that there should not be a debate if President Trump “still has Covid,” just hours after Mr. Trump said he intended to participate in next week’s presidential debate in Miami.
Asked by reporters on Tuesday night whether he would feel safe debating Mr. Trump, who was hospitalized last week with the coronavirus, Mr. Biden responded: “I think if he still has Covid, we shouldn’t have a debate.”
But Mr. Biden said his decision would be guided by the Cleveland Clinic and doctors.
“I think we were gonna have to follow very strict guidelines,” he said. “Too many people have been infected. It’s a very serious problem, so I will be guided by the guidelines of the Cleveland Clinic and what the docs say is the right thing to do.”
Mr. Biden’s remarks introduced fresh uncertainty into the debate calendar and whether either of the two remaining presidential debates would go forward as scheduled, after Mr. Trump revealed last week that he had tested positive for the coronavirus and was later hospitalized.
People with mild to moderate cases of the illness are likely to “remain infectious no longer than 10 days after symptom onset,” according to guidelines from the Centers for Disease Control and Prevention. But that period could be doubled in cases of more serious illness.
Mr. Biden, who shared a debate stage with the president a week ago, tested negative for the coronavirus again on Tuesday, his campaign said.
Mr. Trump tweeted on Tuesday that he planned to attend the next presidential debate, even as he remains infectious and doctors have warned that the course of his illness is unpredictable.
Mr. Biden’s running mate, Senator Kamala Harris, will face off against Vice President Mike Pence in the vice-presidential debate on Wednesday in Salt Lake City. Already, the two candidates will be 12 feet apart, an increase from the seven feet that was originally proposed; they are also expected to be separated by plexiglass, though aides to Mr. Pence said on Tuesday that they thought the barriers were unnecessary.