For reasons that remain unclear, pop star Justin Bieber has challenged Hollywood action hero Tom Cruise to a fight.

The singer, 25, whose Twitter bio reads “Let’s make the world better”, tweeted an open invitation to Cruise, 56, to fight him in the octagon, the UFC equivalent of a boxing ring. “Tom if you don’t take this fight your scared and you will never live it down,” he said (sic).

Bieber than asked UFC president Dana White if he would be willing to host the fight. The businessman did not reply, but Irish professional fighter Conor McGregor responded, tweeting “If Tom Cruise is man enough to accept this challenge, McGregor Sports and Entertainment will host the bout.”

Cruise, who famously performs all his own stunts, has not yet responded.

On a completely unrelated note, here is a video of Tom Cruise punching a horse.