ET caught up with Kidman and Dern at the Calvin Klein Fall 2018 runway show at New York Fashion Week on Tuesday night, and the actresses couldn’t help but fangirl a bit about their new co-star.
"It's amazing!" Dern exclaimed. "When I tell anyone in my life that Meryl Streep is joining us, it's incredible!"
It was announced in January that the three-time Oscar winner would be joining the show for their upcoming season, playing Mary Louise Wright, mother of the deceased Perry Wright (Alexander Skarsgard) and mother-in-law to Kidman's Celeste Wright.
While Dern joked that she felt as if everyone involved in making the show "worked very hard to beg her," Kidman said it didn't take that much convincing to get Streep to sign on.
"Reese and I were just [thinking], 'She would be so amazing in the role!'" Kidman recalled, admitting however that, at first, "We didn't think we'd get her."
"It was written for her and we wanted her," the Lion star said, adding that the whole cast "greatly appreciate" the acclaimed actress' support and faith.
"It really is her standing up and going, 'I support you as women, and I believe in you.' I think that's a big statement from her," Kidman said of Steep's decision to take on the project.
"We're determined to give her an extraordinary experience," Kidman added. "She's had a lot of experiences so we just want to make it fun for her and vibrant and exciting."
Production has not yet begun on the second season of the acclaimed HBO drama, which is expected to premiere sometime in 2019.