Retiring Sen. Jeff Flake on Wednesday refused to rule out mounting a bid to unseat President Donald Trump in 2020, insisting that such a decision is "a long way away."

"That's a long way away. I'm focused on my next 14 months in the Senate, making sure that we get some good policy. Tthere are some things that I want to accomplish in the short term," Flake told ABC's "Good Morning America" in response to a question about his possible presidential aspirations down the road.

Pressed again on the question of a 2020 bid by anchor George Stephanopoulos, Flake reiterated, "You know, that's a long time away. And we'll deal with that when it comes to it."

On Wednesday morning, Trump took to Twitter to criticize Flake and retiring Sen. Bob Corker (R-Tenn.), who also publicly criticized the president Tuesday and previously announced he wouldn't seek reelection.