Tom Petty's relatives are "so touched" after the late rocker's music was featured during the celebrations at U.S. President-elect Joe Biden's victory speech.

The Democrat was declared the winner of a tense election battle with incumbent Donald Trump on Saturday, and hours later, he and his running mate, new Vice President-elect Kamala Harris, addressed the nation from the Biden home base of Wilmington, Delaware.

During the broadcast, Harris, the first female person of colour to take on the job, walked out to Work That by Mary J. Blige, while Biden chose Bruce Springsteen track We Take Care Of Our Own as his entry song. Then, together, they marked the historic occasion by joining hands as Petty's I Won't Back Down was blasted through the speakers and confetti released into the air.

A representative for Petty's family has since taken to Twitter to share their elation at the politicians' choice of music for the victory event.

"We were all so touched to see Tom included on such an important night in America," they posted. "Congratulations @joebiden and @kamalaharris."

The message is in stark contrast to the cease and desist notice Petty's estate officials filed against Trump campaign bosses in June, after the same 1989 track was played at the Republican's re-election campaign rally in Tulsa, Oklahoma.

In a pointed Twitter post at the time, Petty's loved ones wrote: "Trump was in no way authorized to use this song to further a campaign that leaves too many Americans and common sense behind."
The rock legend died in October, 2017.