The Academy of Motion Pictures Arts and Sciences said actor Will Smith was asked to leave the Oscars after he slapped Chris Rock but refused to do so.

Actor Will Smith refused a request to leave Sunday's Oscar ceremony after he slapped presenter Chris Rock, the Academy of Motion Pictures Arts and Sciences said on Wednesday.

"Things unfolded in a way we could not have anticipated,'' Hollywood's film academy said.

"While we would like to clarify that Mr. Smith was asked to leave the ceremony and refused, we also recognize we could have handled the situation differently,'' it added.

The academy said it had started a process that could lead to Smith's expulsion from the group.

Suspension, expulsion or other sanctions may be approved at the body's next board meeting slated for April 18.

On Sunday, during the live telecast of the Oscars, Smith got on to the stage and hit Rock across the face after the comedian made a joke about the appearance of Smith's wife.

Rock joked about Jada Pinkett Smith, as he referenced the 1997 film "G.I. Jane" in which actress Demi Moore had shaved her head.

Jada Smith, whose head is shaved, has in the past spoken about her alopecia diagnosis — a disease that causes hair loss.

After hitting Rock on the stage, Smith returned to his seat and yelled an obscenity at the comedian twice.

Just an hour after the incident, Smith won the trophy for best actor, triggering questions about why he had not been escorted out of the venue.

On Monday, Smith issued a statement apologizing to Rock, the academy and viewers.

He said he was "out of line" and "reacted emotionally."

As per the academy's protocol, Smith has the chance to submit a written response before the group takes action.