From left: Actor Chris Hemsworth, actress Tessa Thompson and director F. Gary Gray attend a Men in Black: International event in Beijing on Sunday. Photo: IC

Men in Black actress Tessa Thompson said she "appreciates the bravery" of her co-star Liam Neeson in facing up to his racist feelings in the past, as the film was released on Wednesday.

The African-American actress - who made her name playing civil rights activist Diane Nash in Selma - said she had been in contact with Neeson since he admitted harboring thoughts about killing a random black man after a woman close to him was raped. 

"I had many conversations via email with Liam," said Thompson, who plays new recruit Agent M opposite Chris Hemsworth in Men in Black: International.

"I realized that in speaking to the press sometimes there can be a huge chasm between what you intend and what your impact is," she said.

Thompson, who has also starred in Creed and the Marvel blockbusters Thor and Avengers, told AFP that she found Neeson, 67, "very responsive" to her concerns.

"I expressed to Liam the importance in my mind of clarifying his heart, because many people who do not have proximity to him would not understand it, and his words would have confused them and for many really hurt and alienated them," she added. 

Neeson holds up a memory eraser used by MIB agents in the poster for the film, with social media wags saying that Hollywood executives probably wished it was real after the outcry he sparked in February while promoting the revenge thriller Cold Pursuit.

The Star Wars and Schindler's List star has been conspicuously absent for the publicity tour to launch the blockbuster which opens in the US on Friday.

A handful of fans demanded he be cut from the movie, as Kevin Spacey was from All The Money In The World after being hit by multiple sexual harassment claims.

However, Neeson has a major role in the film as High T, the head of MIB's London bureau charged with protecting the "Earth from the scum of the universe."

Thompson said she hoped lessons have been learned from Neeson's confession, with the Irish-born actor denying he was a racist and saying he was merely trying to "open up" about latent "racism and bigotry."

"I appreciate his bravery in talking to something that happened in his past," the actress said during a promotional tour in Paris.

"I don't feel a responsibility to speak for him," she added, "but it did allow a real conversation to happen and it was a teachable moment." 

"I think we all need to be conscientious that our words can have a huge effect, particularly if we are in a position of power which celebrity gives you. I am glad he has taken the time to clarify them."