Natalie Portman - Lead
Credit: Jim Spellman/WireImage

Natalie Portman is already garnering Oscar buzz for her role as Jackie Kennedy in the upcoming film Jackie. But taking on the part was a daunting task, even for an actress of Portman's caliber.

She discussed how it felt to tackle the performance on Monday's Today show. "I was terrified because everyone knows what she looks like particularly, and how she sounded," said the Academy Award–winning actress. "And I don't particularly look like her, other than coloring. I've never thought of myself as a sort of mimic or anything. It was scary."

VIDEO: See Natalie Portman in the Jackie Trailer

The iconic First Lady has been depicted by several actresses to date—Katie Holmes and Minka Kelly to name a few—but Portman's portrayal in the Pablo Larraín-directed drama is haunting. In the movie, we get a look into the frightful and culture-shifting days following the assassination of President John F. Kennedy.

And of wearing Jackie Kennedy's unforgettable blood-stained pink Chanel suit, Portman said, "I think it was smart of writer Noah Oppenheimer to focus the film on these days just after the assassination because it sort of gives you a microcosm of who she was as a person."

"To see her in this incredibly pressured situation and to see at that moment when her husband was killed in her lap and how terrifying, awful, and traumatic that is," Portman said. "She had the presence of mind to say 'I'm going to stay in this dress because my image is important right now.' It's important for people to see what this looks like. They were offering to take off this bloody suit and she said, 'No, everyone should see what this is.'"

Catch Jackie in theaters from Dec. 2.