Robert F. Kennedy Jr. continues to face criticism from some prominent family members over his independent presidential bid, with his sister Rory Kennedy telling ABC News anchor George Stephanopoulos on Monday that his bid for the White House makes her "concerned" about the likelihood it could prompt a Donald Trump victory.

Rory Kennedy made the comments on "Good Morning America," where she appeared to tout her new documentary series, "The Synanon Fix."

"My biggest concern with Bobby's run is that he is going to take votes away from [President Joe] Biden," Rory Kennedy said.

Because he is an independent, the success of Robert F. Kennedy Jr's campaign ultimately depends on his ability to access the ballot in key states.

Though he has officially qualified in just one state, Utah, he insists he will be on the ballot everywhere by the time voters head to the polls.

His campaign and an allied super PAC together say they have gathered enough signatures to place him on the ballot in the swing states of Arizona, Georgia, Michigan, Nevada and North Carolina, though officials in each state cannot officially verify his status until later this year.

"I think this election is going to come down to a handful of votes in a handful of states," Rory Kennedy told Stephanopoulos on Monday. "And I am concerned that voting for Bobby is going to take votes away from Biden and lead to a Trump election and I'm very concerned what that will do to our country and to the world over the ensuing four years."

Robert F. Kennedy Jr.'s campaign did not respond to a request for comment on his sister's remarks but the candidate has repeatedly insisted that he and his family members love each other and can disagree despite any policy differences.

He has also pointed out that other relatives support his candidacy.

"I come from a big family [in which] we were raised to debate each other, we were raised to have controversies, to be able to debate robustly and vigorously with each other," he said on NewsNation in January. "We practiced it night after night at the dinner table. And to do that, to disagree with each other without hating on each other, to continue to love each other even though we disagree on issues or on strategies -- I wish that for the whole country,"

The Democratic National Committee has increasingly attacked the Kennedy campaign, claiming that he's "nothing more than a Trump stalking horse," which he rejects.

Many polls show Robert R. Kennedy hurting Biden more than former President Trump in a general election matchup, though a majority of Kennedy supporters who have spoken to ABC News in recent weeks say they would vote for Trump if Kennedy were not running.

Separately over the weekend, the Kennedy campaign reportedly drew rebuke from the family of the late labor organizer Cesar Chavez as the candidate was holding an event to mark Chavez's birthday.

Robert F. Kennedy Jr. told The New York Times that he would have changed the event if he had been aware of the family's views and his campaign said in a statement, in part, that the celebration was meant "to honor Cesar Chavez and his close friendship with my father, my family and me, and his impact on our country."