Halsey has expressed her admiration for South Korean boyband BTS, calling it the "coolest band in the world." Her remark comes after she was spotted cheering on the boys at the "Permission to Dance" concert in Los Angeles' SoFi Stadium Wednesday.

"BTS are the coolest band in the world," the "Be Kind" singer wrote in a tweet.

"Halsey" became a trending topic on Twitter on Thursday after hundreds of thousands of fans, more commonly known as ARMYs, approved of their post.

The fans even came up with a nickname for the singer — "the ARMYs mom."

"She is army's mom @halsey," a fan who has the handle @halseyfkfk said.

Another supporter, who has the username @elanaurora25 on the platform, wanted to make sure Halsey would be comfortable being addressed as the fandom's mom. Sharing a photo of the singer during the boys' concert, the fan asked, "Armys have seen how much and sincere the love you give to BTS is. So can we call you 'Mom of Armys?'"

Halsey responded to the tweet, writing, "It's funny you guys call me mom cause in Halo, Dr. Halsey kidnapped a bunch of kids and constructed an army of them and it's like me too."

The singer also took to their Instagram page Thursday to share a carousel of images showing them having a great time at the group's concert. The snaps included an OOTD and a photo with their son, Ender Ridley Aydin. Shots showing a BTS lightstick, the colorful stage and the singer posing with the boys backstage were also featured in the post.

"uncle gang __ beyond words," Halsey wrote in the caption.

Several ARMYs also posted photos and clips showing the singer rocking to BTS songs on the third day of the group's four-day concert. At some point, the singer was shown on the gigantic LED screen as she was enjoying the show and showing support for the boys.

Before giving birth in July, the "Without Me" singer revealed their food cravings and posted a photo of a fast-food joint's recognizable brown paper bag via Instagram Stories. At that time, BTS was endorsing a meal that included special sauces inspired by South Korean recipes.

"Baby is Army," they wrote on the said story, which was then captured and tweeted by a fan account.

It can be recalled that Halsey collaborated with BTS for the 2019 track, "Boy With Luv," which climbed to the No. 8 spot on Billboard Hot 100 after its release.

South Korean boy band BTS perform during the 2020 MTV Video Music Awards BTS is back live in action with their "Permission To Dance" concert in LA. Photo: MTV / -