Story highlights "I don't rule anything out, but it's not in my plans," Flake said

Flake is a frequent critic of President Donald Trump

(CNN) Sen. Jeff Flake says he isn't ruling out a 2020 presidential run following his term in the Senate.

The Arizona Republican, who announced in October he would not be seeking re-election in 2018, told ABC's "This Week" in an interview that aired Sunday that he doesn't have any formal plans to run for President following his time on Capitol Hill.

"I don't rule anything out, but it's not in my plans," Flake said.

Flake, a frequent critic of President Donald Trump, announced his decision to retire with a speech on the Senate floor that bemoaned the "coarsening" tenor of politics in the United States, and criticized his own party's "complicity" with Trump's behavior.

On "This Week," Flake was asked if he would consider running as a Republican or an independent.

Read More