Warner Bros Japan has demanded action against Barbenheimer tweets shared by its US head office, The Guardian reported. The organisation described the fan-drive movement as “extremely regrettable”.

The development follows an opposition in Japan against the merging of Greta Gerwig’s Barbie with Oppenheimer of Christopher Nolan.

“Because the movies Barbie and Oppenheimer were both released in the US on 21 July, there is currently a movement driven by overseas fans to watch them together (#Barbenheimer), but this is not an official movement. We find the reaction to this fan-driven movement from the official US account for the movie Barbie to be extremely regrettable. We take this very seriously and are asking the US head office to take appropriate action. We apologise to those offended by these inconsiderate actions,” said a translation of the statement, which was posted on Japan’s Twitter account for the Barbie film.

“Barbenheimer” became the buzzword on social media with the timely same-day release of Barbie and Oppenheimer. Users have been sharing memes and art combining the pink imagery of Barbie with mushroom clouds and fiery explosions in Oppenheimer.

But Japan was an exception where #NoBarbenheimer was trending last week. Some social media users did not like the concept of Barbenheimer and described it as “trivialising” nuclear weapons and the impact the bombings had on Japan.

“The official Barbie movie account is completely on board with the atomic bomb and mushroom cloud memes, so Barbie is a no-go as well,” said a #nobarbenheimer post, which was viewed seven million times.

Warner Bros Japan’s statement came after the official US Twitter account for Barbie reacted positively to several Barbenheimer images shared by fans.

Barbie is due to be released in Japan this month but Japan’s largest distributor of Hollywood films Toho-Towa has yet to announce a release date for Oppenheimer.

Margot Robbie and Ryan Gosling’s starrer movie has so far collected $775m globally while the biopic on J Robert Oppenheimer has made $400m.