Bacall (right) dismissed suggestions Kidman was a screen legend

The premiere of Birth followed a booing from critics, while in an interview, Bacall dismissed suggestions Kidman was a legend, labelling her a "beginner".

In Birth, Kidman's character believes her husband is reincarnated as a boy, with whom she shares a bath and a kiss.

"I wanted to make a film where you understand love," said Kidman.

At the film's press conference on Wednesday, Kidman grew frustrated that all the questions were directed at her.

She can't be a legend, you have to be older Lauren Bacall on Nicole Kidman Head to head: Kidman v Bacall

"Please ask somebody else," she told journalists.

But when one reporter asked other panel members who they would like to be reincarnated as, Bacall refused to answer.

"It's not a fascinating question," she said. "No offence."

'Screen legend'

In an earlier interview with the UK's GMTV, Bacall had been asked about working with "screen legend Nicole Kidman".

"She's not a legend," Bacall interrupted. "She's a beginner. What is this legend? She can't be a legend at whatever age she is. She can't be a legend, you have to be older."

Birth is in the running for the festival's main Golden Lion prize

Aged 79, Bacall is the widow of Humphrey Bogart and starred in classic films including The Big Sleep and Key Largo.

At the press conference, she said she and Kidman had a "fabulous relationship on screen and off".

"I love working with a young actress," she said. "Nicole and I worked together on Dogville and we were friends when we started this."

Kidman, who won an Oscar in 2003, said she took the part because the film "spoke to me".

"I read the script and it immediately affected me. There was something in this woman I felt I understood and knew," she said.

I would hope I only make films that some people like and some people don't Jonathan Glazer Director

"I responded to this woman who was in mourning. It wasn't that I wanted to make a film where I kiss a 10-year-old boy."

Birth was directed by Jonathan Glazer, who also made Sexy Beast.

"You can't aim to please everybody," he said, referring to the negative response from some critics.

"I would hope I only make films that some people like and some people don't."