Sen. Susan Collins, R-Maine, is unfazed by the possibility of running against Susan Rice, former national security adviser to President Barack Obama.

Rice signaled she would consider running against Collins in 2020 and said that Maine and the U.S. “deserve better,” comments that came after Collins announced she would vote to confirm now-Supreme Court Justice Brett Kavanaugh last week.

"I really have little interest in what she has to say," Collins told CNN Wednesday. "She's not a legal resident of the state of Maine."

Collins then said "she'd have to move to the state to become a legal resident."

[Related: Susan Collins: Everybody knows Susan Rice doesn't live in Maine]

A spokesperson for Rice declined to comment.

Over the weekend, Rice said at an event that she has owned a home in Maine for "the last 20-so years," so running for office in Maine is "not completely crazy."

Rice first prompted speculation when she appeared to throw her name in the ring via Twitter as a potential candidate to challenge Collins.

“Who wants to run for Senate in Maine? there will be an army of supporters with you,” Obama’s former White House communications director Jen Psaki asked in a tweet on Friday.

“Me,” Rice responded.

"Many thanks for the encourgement. I’m not making any announcements. Like so many Americans, I am deeply disappointed in Sen. Collins’ vote for Kavanaugh. Maine and America deserve better," Rice said in a separate tweet on Friday.