Liz Cheney speaks with David Remnick during The 2024 New Yorker Festival Oct. 26. Craig Barritt/Getty Images for The New Yorker

Former Republican Rep. Liz Cheney said "it's time" former President George W. Bush endorses Vice President Kamala Harris for president.

Cheney, of Wyoming, is backing Harris as is her father, Dick Cheney, who served as Bush's vice president during the two terms of his administration.

"I can't explain why George W. Bush hasn't spoken out but I think it's time, and I wish that he would," Cheney said during an appearance Oct. 26 at The New Yorker Festival.

A growing number of Republicans, including those who served in the Donald Trump and Bush administrations, have come out in support of the vice president.

This week, Barbara Pierce Bush, the former president's daughter, threw her support behind Harris and campaigned for her in battleground Pennsylvania.

"It was inspiring to join friends and meet voters with the Harris-Walz campaign in Pennsylvania this weekend," Barbara told People Magazine, referring to Harris' running mate Tim Walz.

"I'm hopeful they'll move our country forward and protect women's rights," Bush, 42, said.

After Liz Cheney came out for Harris in September, Bush's office said neither the former president or former first lady Laura Bush would be endorsing a presidential candidate this year.

"President Bush retired from presidential politics years ago," his office told NBC News.

Cheney called Trump a "petty, vindictive, cruel, unstable man" after he said in an interview Thursday evening that said she should have "guns trained on her face."

"We cannot entrust our country and our freedom to a petty, vindictive, cruel, unstable man who wants to be a tyrant," she said in a posting on X, adding #Womenwillnotbesilenced #VoteKamala.