President Donald Trump attacked his November opponent Joe Biden on Friday after the Democratic presidential candidate suggested the African-American community lacked diversity in its views.
Biden later clarified his comments but Trump seized on them in an apparent bid to drum up support among black voters, who overwhelmingly favour the Democrat in opinion polls.
"After yesterday's statement, Sleepy Joe Biden is no longer worthy of the Black Vote!" Trump tweeted.
During an interview on Thursday with a National Public Radio reporter, Biden said the country's Latino community was "incredibly diverse."
"Unlike the African American community, with notable exceptions, the Latino community is an incredibly diverse community with incredibly diverse attitudes about different things," Biden said.
"You go to Florida, you find a very different attitude about immigration than you do in Arizona. So it's a very diverse community."
Biden later issued a series of tweets clarifying his remarks.
"Earlier today, I made some comments about diversity in the African American and Latino communities that I want to clarify," he said. "In no way did I mean to suggest the African American community is a monolith - not by identity, not on issues, not at all.
"Throughout my career I've witnessed the diversity of thought, background, and sentiment within the African American community. It's this diversity that makes our workplaces, communities, and country a better place," he said.
Biden, 77, who served for eight years as vice president to Barack Obama, America's first black president, enjoys strong support among black voters.
They helped power him to the Democratic presidential nomination and will be a key voting bloc in his bid to defeat Trump on November 3.
In a Washington Post-Ipsos poll in June, 92 percent of the black registered voters surveyed said they would vote for Biden.
Only five percent backed Trump while 90 percent of those surveyed said they do not think the Republican president is sympathetic to the problems of black Americans.