Sen. Jeff Flake (R-Ariz.) on Sunday said that Republican leaders who do not call out President Trump are complicit.

"I do think so," Flake told CBS's "Face the Nation" when asked if GOP leaders are complicit if they fail to call out Trump.

"I think that you know, obviously the last thing you want to do is wake up every morning and see a tweet and think, 'I just' - you know, it's tough not to just say, 'I'm not going to respond.' And we can't respond to everything. But there are times when you have to stand up and say, 'I'm sorry. This is wrong.'"

Flake said elected officials must hold each other responsible, whether it's in the White House or in Congress.

"There are truths that are self-evident. And you've got to stand up and call, whether it's the White House or other elected officials, to task when they're not doing what they should," he said.