K-pop superstar BTS has grabbed the honor of having the most sold digital song of the year in the United States for the second time.

"Butter" was the most sold digital song of the year in the country with 1.89 million downloads sold, according to an annual year-end report released jointly by MRC Data and Billboard on Thursday (US time). In 2020, the group's "Dynamite" was the top seller with 1.26 million sold.

The summery disco-pop song was released in May as the group's second English-language song and stayed 10 non-consecutive weeks atop the Billboard Hot 100 chart. Including "Butter," only 40 songs have achieved the feat in Billboard history.

Coming in a distant second place in the year-end ranking was "Fancy Like" by Walker Hayes, which sold 499,000 downloads.

"Butter" was the only song that sold more than 1 million downloads in the country last year.

The South Korean group showed a strong presence in the digital song sales category.

It took four of the top 10 posts, with "Permission to Dance" in third with 404,000 downloads; "Dynamite" in sixth with 308,000 downloads; and "My Universe," a collaboration single with British rock band Coldplay, in seventh place with 287,000 downloads.

BTS topped the top-selling physical album list with its fourth full-length album "Map of the Soul: 7" in 2020 but failed to hit the list last year. (Yonhap)