LOS ANGELES (AFP) - Actor Brad Pitt described a Ukrainian prankster who attacked him last week as a "nutter", in his first public comments on the incident on a Hollywood red carpet.

In an exclusive statement to People magazine, he described how Vitalii Sediuk, 25, dived at his crotch while the megastar was signing autographs at the premiere of his partner Angelina Jolie's latest film.

"I was at the end of the line signing autographs, when out of the corner of my eye I saw someone stage-diving over the barrier at me," Pitt said of the attack on the red carpet for Maleficent. "I took a step back; this guy had latched onto my lapels. I looked down and the nutter was trying to bury his face in my crotch," he added.

Pitt described how he "cracked him twice in the back of the head - not too hard - but enough to get his attention, because he did let go.

"I think he was then just grabbing for a hand hold because the guys were on him, and he reached up and caught my glasses," Pitt said.

Sediuk, who has done a number of similar stunts in recent years, was put on three years' probation on Friday and ordered to undergo psychological counselling after pleading no contest to two charges against him.

He was also given 20 days of community labour and told to remain at least 500m away from Pitt and Jolie, and stay away from the Hollywood & Highland Centre - the home of the Academy Awards.

Pitt said: "I don't mind an exhibitionist, but if this guy keeps it up he's going to spoil it for the fans who have waited up all night for an autograph or a selfie, because it will make people more wary to approach a crowd.

"And he should know, if he tries to look up a woman's dress again, he's going to get stomped" - referring to an incident when Sediuk put his head under actress America Ferrera's gown at this year's Cannes film festival.

Other targets of his affection have included Will Smith, Madonna, British singer Adele and Leonardo DiCaprio. In February 2013, he gatecrashed the Grammy music awards, going up on stage after presenter Jennifer Lopez read out Adele's name.